SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                ----------------

                                 SCHEDULE 13G/A
                                 (Rule 13d-102)
                                ----------------

              INFORMATION TO BE INCLUDED IN STATEMENTS PURSUANT TO
                   RULES 13d-1(b), (c) AND (d) AND AMENDMENTS
                    THERETO FILED PURSUANT TO 13d-2 UNDER THE
                         SECURITIES EXCHANGE ACT OF 1934
                               (Amendment No. 1)*

                           DUSA Pharmaceuticals, Inc.
                                (Name of Issuer)

                      Common Stock, no par value per share
                         (Title of Class of Securities)

                                    266898105
                                 (CUSIP Number)

                                December 31, 2006
             (Date of Event Which Requires Filing of this Statement)


     Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:
     [ ] Rule 13d-1(b)
     [X] Rule 13d-1(c)
     [ ] Rule 13d-1(d)

                              (Page 1 of 13 Pages)
-----------

     * The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.


     The information required in the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).



Schedule 13G/A                                              PAGE 2 of 13
CUSIP No. 266898105

     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
            Phaeton International (BVI) Ltd.
            None
------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                               (a)  [ ]
                                                               (b)  [X]
------------------------------------------------------------------------
     (3)  SEC USE ONLY

------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
            British Virgin Islands
------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ---------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    419,600
OWNED BY       ---------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ---------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    419,600
------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
            419,600
------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                        [ ]
------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
            2.15%
------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
            CO
------------------------------------------------------------------------



Schedule 13G/A                                              PAGE 3 of 13
CUSIP No. 266898105

     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
            Phoenix Partners, L.P.
            13-6272912
------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                               (a)  [ ]
                                                               (b)  [X]
------------------------------------------------------------------------
     (3)  SEC USE ONLY

------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
            New York
------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ---------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    423,400
OWNED BY       ---------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ---------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    423,400
------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
            423,400
------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                        [ ]
------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
            2.17%
------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
            PN
------------------------------------------------------------------------



Schedule 13G/A                                              PAGE 4 of 13
CUSIP No. 266898105

     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
            Phoenix Partners II, L.P.
            84-1631449
------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                               (a)  [ ]
                                                               (b)  [X]
------------------------------------------------------------------------
     (3)  SEC USE ONLY

------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
            Delaware
------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ---------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    101,000
OWNED BY       ---------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ---------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    101,000
------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
            101,000
------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                        [ ]
------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
            0.52%
------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
            PN
------------------------------------------------------------------------



Schedule 13G/A                                              PAGE 5 of 13
CUSIP No. 266898105

     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
            Phoenix Partners III, L.P.
            32-0145065
------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                               (a)  [ ]
                                                               (b)  [X]
------------------------------------------------------------------------
     (3)  SEC USE ONLY

------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
            Delaware
------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ---------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    18,600
OWNED BY       ---------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ---------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    18,600
------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
            18,600
------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                        [ ]
------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
            0.1%
------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
            PN
------------------------------------------------------------------------



Schedule 13G/A                                              PAGE 6 of 13
CUSIP No. 266898105

     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
            Morgens, Waterfall, Vintiadis & Co., Inc.
            13-2674766
------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                               (a)  [ ]
                                                               (b)  [X]
------------------------------------------------------------------------
     (3)  SEC USE ONLY

------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
            New York
------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ---------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    962,600
OWNED BY       ---------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ---------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    962,600
------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
            962,600
------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                        [ ]
------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
            4.94%
------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
            IA
------------------------------------------------------------------------



Schedule 13G/A                                              PAGE 7 of 13
CUSIP No. 266898105

     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
            Edwin H. Morgens
------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                               (a)  [ ]
                                                               (b)  [X]
------------------------------------------------------------------------
     (3)  SEC USE ONLY

------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
            United States
------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    6,000
SHARES         ---------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    962,600
OWNED BY       ---------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    6,000
REPORTING      ---------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    962,600
------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
            968,600
------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                        [ ]
------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
            4.97%
------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
            IN
------------------------------------------------------------------------



Schedule 13G/A                                              PAGE 8 of 13
CUSIP No. 266898105

     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
            John C. Waterfall
------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                               (a)  [ ]
                                                               (b)  [X]
------------------------------------------------------------------------
     (3)  SEC USE ONLY

------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
            United States
------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ---------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    962,600
OWNED BY       ---------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ---------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    962,600
------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
            962,600
------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                        [ ]
------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
            4.94%
------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
            IN
------------------------------------------------------------------------



Schedule 13G/A                                              PAGE 9 of 13
CUSIP No. 266898105

ITEM 1(a).  NAME OF ISSUER:
               DUSA Pharmaceuticals, Inc. (the "Company")

ITEM 1(b).  ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:
               25 Upton Drive, Wilmington, MA 01887

ITEM 2(a).  NAME OF PERSON FILING:
               This Schedule 13G is filed jointly by (a) Phaeton International
               (BVI) Ltd. ("Phaeton"), (b) Phoenix Partners, L.P. ("Phoenix"),
               (c) Phoenix Partners II, L.P.("Phoenix II"), (d) Phoenix Partners
               III, L.P.("Phoenix III"), (e) Morgens, Waterfall, Vintiadis &
               Company, Inc. ("Morgens Waterfall" (f) Edwin H. Morgens
               ("Morgens") and (g) John C. Waterfall ("Waterfall" and together
               with the persons listed in (a) through (f), the "Reporting
               Persons").

               Phaeton, Phoenix, Phoenix II and Phoenix III are hereinafter
               sometimes collectively referred to as the "Advisory Clients".

ITEM 2(b).  ADDRESS OF PRINCIPAL OFFICE OR, IF NONE, RESIDENCE:
               The business address of each of the Reporting Persons is 600
               Fifth Avenue, 27th Floor, New York NY 10020.

ITEM 2(c).  CITIZENSHIP:
               Phoenix is a limited partnership organized under the laws of the
               State of New York. Phoenix II is a limited partnership organized
               under the laws of the State of Delaware. Phoenix III is a limited
               partnership organized under the laws of the State of Delaware.
               Phaeton is an exempted company organized in British Virgin
               Islands. Morgens Waterfall is a corporation organized under the
               laws of the State of New York. Each of Morgens and Waterfall are
               United States citizens.

ITEM 2(d).  TITLE OF CLASS OF SECURITIES:
               Common Stock, no par value per share

ITEM 2(e).  CUSIP NUMBER:
               266898105.

ITEM 3. IF THIS STATEMENT IS FILED PURSUANT TO 13d-1(b) OR 13d-2(b) OR (c),
CHECK WHETHER THE PERSON FILING IS A:

        (a) [ ] Broker or dealer registered under Section 15 of the Act

        (b) [ ] Bank as defined in Section 3(a)(6) of the Act

        (c) [ ] Insurance Company as defined in Section 3(a)(19) of the Act


        (d) [ ] Investment Company registered under Section 8 of the
                Investment Company Act of 1940

        (e) [ ] Investment Adviser registered under Section 203 of the
                Investment Advisers Act of 1940: see Rule 13d-1(b)(1)(ii)(E)



Schedule 13G/A                                              PAGE 10 of 13
CUSIP No. 266898105

        (f) [ ] Employee Benefit Plan, Pension Fund which is subject to the
                provisions of the Employee Retirement Income Security Act of
                1974 or Endowment Fund; see Rule 13d-1(b)(1)(ii)(F)

        (g) [ ] Parent Holding Company, in accordance with Rule 13d-1(b)(ii)(G);


        (h) [ ] Savings Associations as defined in Section 3(b) of the Federal
                Deposit Insurance Act;

        (i) [ ] Church Plan that is excluded from the definition of an
                investment company under Section 3(c)(14) of the Investment
                Company Act of 1940;

        (j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

     IF THIS STATEMENT IS FILED PURSUANT TO Rule 13d-1(c),
     CHECK THIS BOX.                                           [x]

ITEM 4.  OWNERSHIP.

     The percentages used herein are calculated based on the shares issued and
outstanding as of November 3, 2006, as reported in the Company's quarterly
report on Form 10-Q filed with the Securities and Exchange Commission by the
Company for the quarterly period ending September 30, 2006.

     A.   Phaeton International (BVI) Ltd
               (a) Amount beneficially owned: 419,600
               (b) Percent of class: 2.1%
               (c)(i) Sole power to vote or direct the vote: -0-
                 (ii) Shared power to vote or direct the vote: 419,600
                (iii) Sole power to dispose or direct the disposition: -0-
                 (iv) Shared power to dispose or direct the disposition:
                      419,600

     B.   Phoenix Partners, L.P.
               (a) Amount beneficially owned: 423,400
               (b) Percent of class: 2.2%
               (c)(i) Sole power to vote or direct the vote: -0-
                 (ii) Shared power to vote or direct the vote: 423,400
                (iii) Sole power to dispose or direct the disposition: -0-
                 (iv) Shared power to dispose or direct the disposition:
                      423,400

     C.   Phoenix Partners II, L.P.
               (a) Amount beneficially owned: 101,000
               (b) Percent of class: 0.6%
               (c)(i) Sole power to vote or direct the vote: -0-
                 (ii) Shared power to vote or direct the vote: 101,000
                (iii) Sole power to dispose or direct the disposition: -0-
                 (iv) Shared power to dispose or direct the disposition:
                      101,000



Schedule 13G/A                                              PAGE 11 of 13
CUSIP No. 266898105

     D.   Phoenix Partners III, L.P.
               (a) Amount beneficially owned: 18,600
               (b) Percent of class: 0.1%
               (c)(i) Sole power to vote or direct the vote: -0-
                 (ii) Shared power to vote or direct the vote: 18,600
                (iii) Sole power to dispose or direct the disposition: -0-
                 (iv) Shared power to dispose or direct the disposition:
                      18,600


     E.   Morgens, Waterfall, Vintiadis & Co., Inc.
               (a) Amount beneficially owned: 962,600
               (b) Percent of class: 4.94
               (c)(i) Sole power to vote or direct the vote: -0-
                 (ii) Shared power to vote or direct the vote: 962,600
                (iii) Sole power to dispose or direct the disposition: -0-
                 (iv) Shared power to dispose or direct the disposition:
                      962,600

     F. Edwin H. Morgens
               (a) Amount beneficially owned: 968,600
               (b) Percent of class: 4.97
               (c)(i) Sole power to vote or direct the vote: 6,000
                 (ii) Shared power to vote or direct the vote: 968,600
                (iii) Sole power to dispose or direct the disposition: 6,000
                 (iv) Shared power to dispose or direct the disposition:
                      962,600

     G. John C. Waterfall
               (a) Amount beneficially owned: 962,600
               (b) Percent of class: 4.94
               (c)(i) Sole power to vote or direct the vote: -0-
                 (ii) Shared power to vote or direct the vote: 962,600
                (iii) Sole power to dispose or direct the disposition: -0-
                 (iv) Shared power to dispose or direct the disposition:
                      962,600


ITEM 5.   OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.
                  If this statement is being filed to report the fact that as of
                  the date hereof the reporting person has ceased to be the
                  beneficial owner of more than five percent of the class of
                  securities, check the following [x].


ITEM 6.   OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.
                  Morgens Waterfall is an investment adviser registered under
                  Section 203 of the Investment Advisers Act of 1940, as
                  amended. The business of Morgens Waterfall is the rendering of
                  financial services and as such it provides discretionary
                  investment advisory services to each of the Advisory Clients.
                  In such capacity, Morgens Waterfall has the power to make
                  decisions regarding the dispositions of the proceeds from the
                  sale of the foregoing shares of Common Stock. Under the rules
                  promulgated by the Securities and Exchange Commission, Morgens
                  Waterfall and its principals (Morgens and Waterfall) may be
                  considered "beneficial owners" of securities acquired by the



Schedule 13G/A                                              PAGE 12 of 13
CUSIP No. 266898105

                  Advisory Clients. Each such Advisory Client has the right to
                  receive or the power to direct the receipt of dividends from,
                  or the proceeds from the sale of, the securities held in such
                  person's account.


ITEM      7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
          THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY.
                  Not applicable.

ITEM 8.   IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.
                  Not applicable.

ITEM 9.   NOTICE OF DISSOLUTION OF GROUP.
                  Not applicable.

ITEM 10.  CERTIFICATION.  (if filing pursuant to Rule 13d-1(c))
                  By signing below each Reporting Person certifies that, to the
                  best of its knowledge and belief, the securities referred to
                  above were not acquired and are not held for the purpose of or
                  with the effect of changing or influencing the control of the
                  issuer of the securities and were not acquired and are not
                  held in connection with or as a participant in any transaction
                  having that purpose or effect.



Schedule 13G/A                                              PAGE 13 of 13
CUSIP No. 266898105
                                    SIGNATURE

      After reasonable inquiry and to the best of our knowledge and belief, the
undersigned certify that the information set forth in this statement is true,
complete and correct.

DATED:  February 7, 2007


                                    --------------------------
                                    Edwin H. Morgens,
                                    as attorney-in-fact for
                                    the Reporting Persons