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                               UNITED STATES                                OMB APPROVAL
                    SECURITIES AND EXCHANGE COMMISSION             ------------------------------
                          Washington, D.C. 20549                   OMB Number 3235-0145
                                                                   ------------------------------
                                                                   Expires:   February 28, 2009
                                                                   ------------------------------
                                                                   Estimated average burden
                                                                   hours per response . . . 11


                                  SCHEDULE 13G


                    Under the Securities Exchange Act of 1934
                                (Amendment No.1)


                             Modtech Holdings, Inc.
-------------------------------------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
-------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    60783C100
-------------------------------------------------------------------------------
                                 (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:

        |x|       Rule 13d-1(b)

                  Rule 13d-1(c)

                  Rule 13d-1(d)


*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).








                                PAGE 1 OF 8 PAGES





----------------------                                    ---------------------
CUSIP No. 60783C100                 13G                   Page  2  of  8  Pages
----------------------                                    ---------------------

-------------------------------------------------------------------------------
        
    1      NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only).

           Manulife Financial Corporation

-------------------------------------------------------------------------------
    2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*      (a)  |_|
                                                                  (b)  |_|
           N/A
-------------------------------------------------------------------------------
    3      SEC USE ONLY

-------------------------------------------------------------------------------
    4      CITIZENSHIP OR PLACE OF ORGANIZATION

           Canada

-------------------------------------------------------------------------------
                       5     SOLE VOTING POWER

                             -0-
                       --------------------------------------------------------
    Number of          6     SHARED VOTING POWER
      Shares
   Beneficially              -0-
     Owned by          --------------------------------------------------------
       Each            7     SOLE DISPOSITIVE POWER
    Reporting
      Person                 -0-
       With            --------------------------------------------------------
                       8     SHARED DISPOSITIVE POWER

                             -0-
--------------------------------------------------------------------------------
    9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

          None,  except through its indirect,  wholly-owned  subsidiaries,  John
          Hancock Advisers, LLC and MFC Global Investment Management (U.S.), LLC
--------------------------------------------------------------------------------
   10     CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

          N/A
--------------------------------------------------------------------------------
   11     PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

          See line 9, above.
--------------------------------------------------------------------------------
   12     TYPE OF REPORTING PERSON*

          HC
--------------------------------------------------------------------------------

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!
                                PAGE 2 OF 8 PAGES





----------------------                                    ---------------------
CUSIP No. 60783C100                 13G                   Page  3  of  8  Pages
----------------------                                    ---------------------

-------------------------------------------------------------------------------
        
    1      NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only).

           John Hancock Advisers, LLC

-------------------------------------------------------------------------------
    2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*      (a)  |_|
                                                                  (b)  |_|
           N/A
-------------------------------------------------------------------------------
    3      SEC USE ONLY

-------------------------------------------------------------------------------
    4      CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
-------------------------------------------------------------------------------
                       5     SOLE VOTING POWER

                             -0-
                       --------------------------------------------------------
    Number of          6     SHARED VOTING POWER
      Shares
   Beneficially              1,131,318
     Owned by          --------------------------------------------------------
       Each            7     SOLE DISPOSITIVE POWER
    Reporting
      Person                 -0-
       With            ---------------------------------------------------------
                       8     SHARED DISPOSITIVE POWER

                             1,131,318
-------------------------------------------------------------------------------
    9      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           1,131,318
-------------------------------------------------------------------------------
   10      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

           N/A
-------------------------------------------------------------------------------
   11      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

           5.65%
-------------------------------------------------------------------------------
   12      TYPE OF REPORTING PERSON*

           IA
-------------------------------------------------------------------------------

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!
                                PAGE 3 OF 8 PAGES





----------------------                                    ---------------------
CUSIP No. 60783C100                 13G                   Page  4  of  8  Pages
----------------------                                    ---------------------

-------------------------------------------------------------------------------
        
    1      NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only).

           MFC Global Investment Management (U.S.), LLC

-------------------------------------------------------------------------------
    2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*      (a)  |_|
                                                                  (b)  |_|
           N/A
-------------------------------------------------------------------------------
    3      SEC USE ONLY

-------------------------------------------------------------------------------
    4      CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
-------------------------------------------------------------------------------
                       5     SOLE VOTING POWER

                             264,140
                       --------------------------------------------------------
    Number of          6     SHARED VOTING POWER
      Shares
   Beneficially              1,131,318
     Owned by          --------------------------------------------------------
       Each            7     SOLE DISPOSITIVE POWER
    Reporting
      Person                 264,140
       With            ---------------------------------------------------------
                       8     SHARED DISPOSITIVE POWER

                             1,131,318
-------------------------------------------------------------------------------
    9      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           1,395,458
-------------------------------------------------------------------------------
   10      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

           N/A
-------------------------------------------------------------------------------
   11      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

           6.97%
-------------------------------------------------------------------------------
   12      TYPE OF REPORTING PERSON*

           IA
-------------------------------------------------------------------------------

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!
                                PAGE 4 OF 8 PAGES




Attention:  Intentional  misstatements  or omissions of fact constitute  Federal
            criminal violations (See 18 U.S.C. 1001)

   Item 1(a)    Name of Issuer:
                Modtech Holdings, Inc.

   Item 1(b)    Address of Issuer's Principal Executive Offices:
                2830 Barrett Avenue
                Perris, CA 92571

   Item 2(a)    Name of Person Filing:
                This filing is made on behalf of Manulife Financial  Corporation
                ("MFC"),  and MFC's indirect,  wholly-owned  subsidiaries,  John
                Hancock   Advisers,   LLC  ("JHA")  and  MFC  Global  Investment
                Management (U.S.), LLC ("MFC Global (U.S.)").

   Item 2(b)    Address of the Principal Offices:
                The principal  business  offices of MFC are located at 200 Bloor
                Street, East, Toronto,  Ontario,  Canada, M4W 1E5. The principal
                business  offices  of JHA are  located at 601  Congress  Street,
                Boston,  Massachusetts  02210. The principal business offices of
                MFC Global (U.S.) are located at 101 Huntington Street,  Boston,
                Massachusetts 02199.

   Item 2(c)    Citizenship:
                MFC is organized  and exists under the laws of Canada.
                JHA and MFC Global  (U.S.) are  organized  and exist  under the
                laws of the State of Delaware.

   Item 2(d)    Title of Class of Securities:
                Common Stock

   Item 2(e)    CUSIP Number:
                60783C100

   Item 3       If the Statement is being filed  pursuant to Rule  13d-1(b),  or
                13d-2(b), check whether the person filing is a:

                MFC:     (g) (X) Parent  Holding  Company,  in accordance  with
                                 ss.240.13d-1(b)(ii)(G).

                JHA:     (e) (X) Investment  Adviser registered under ss.203 of
                                 the Investment Advisers Act of 1940.

                MFC Global
                (U.S.):  (e) (X) Investment  Adviser registered under ss.203 of
                                 the Investment Advisers Act of 1940.

   Item 4       Ownership:

                (a) Amount Beneficially  Owned: JHA has beneficial  ownership of
                    1,131,318  shares  and  MFC  Global  (U.S.)  has  beneficial
                    ownership of 1,395,458  shares of Common Stock.  Through its
                    parent-subsidiary relationship to JHA and MFC Global (U.S.),
                    MFC may be deemed to have beneficial ownership of these same
                    shares.


                                PAGE 5 OF 8 PAGES


               (b)  Percent of Class: Of the 20,018,855 shares outstanding as of
                    November 6, 2006, according to the issuer's quarterly report
                    on form 10-Q for the period ended  September  30, 2006,  JHA
                    held 5.65% and MFC Global  (U.S.) held 6.97%.  The aggregate
                    percentage  held as of December 31, 2006 (after  eliminating
                    double  counting as a result of shared  investment or voting
                    discretion) by all reporting persons was 6.97%.

               (c) Number of shares as to which the person has:

                   (i)  sole power to vote or to direct the vote:
                        MFC  Global  (U.S.)  has sole power to vote or to direct
                        the  voting  of  264,140   shares  of  Common  Stock  it
                        beneficially owns.

                   (ii) shared power to vote or to direct the vote:
                        JHA has shared  power to vote or to direct the voting of
                        the shares of Common  Stock it  beneficially  owns.  MFC
                        Global  (U.S.) has shared power to vote or to direct the
                        voting  of   1,131,318   shares   of  Common   Stock  it
                        beneficially owns.

                   (iii)sole power to dispose or  to direct the disposition of:
                        MFC Global (U.S.) has sole power to dispose or to direct
                        the  disposition  of 264,140  shares of Common  Stock it
                        beneficially owns.

                   (iv) shared power to dispose or to direct the disposition of:
                        JHA  has  shared  power  to  dispose  or to  direct  the
                        disposition   of  the   shares   of   Common   Stock  it
                        beneficially owns. MFC Global (U.S.) has shared power to
                        dispose or to direct the disposition of 1,131,318 shares
                        of Common Stock it beneficially owns.

   Item 5       Ownership of Five Percent or Less of a Class:
                Not applicable.

   Item 6       Ownership of More than Five Percent on Behalf of Another Person:
                Not applicable.

   Item 7       Identification and Classification of the Subsidiary which
                Acquired the Security Being Reported on by the Parent Holding
                Company:
                See Items 3 and 4 above.

   Item 8       Identification and Classification of Members of the Group:
                Not applicable.

   Item 9       Notice of Dissolution of a Group:
                Not applicable.

   Item 10      Certification:
                By signing below the undersigned certifies that, to the best of
                its knowledge and belief, the securities referred to above were
                acquired  and are held in the  ordinary  course of business and
                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.


                             PAGE 6 OF 8 PAGES


                                 SIGNATURE

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


                                Manulife Financial Corporation


                                By:      /s/ Scott A. Lively
                                Name:    Scott A. Lively
Dated: February 6, 2007         Title:   Attorney in Fact*


                                John Hancock Advisers, LLC


                                By:      /s/ Francis V. Knox Jr.
                                Name:    Francis V. Knox Jr.
Dated: February 6, 2007         Title:   Vice President and Chief Compliance
                                         Officer


                                MFC Global Investment Management (U.S.), LLC


                                By:      /s/ Francis V. Knox Jr.
                                Name:    Francis V. Knox Jr.
Dated: February 6, 2007         Title:   Vice President and Chief Compliance
                                         Officer


* Signed  pursuant to a Power of Attorney dated January 31, 2007 included as an
  Exhibit to Schedule 13G filed with the Securities and Exchange  Commission by
  Manulife Financial Corporation on February 1, 2007.


                                PAGE 7 OF 8 PAGES


EXHIBIT A
                             JOINT FILING AGREEMENT
                             ----------------------

     Manulife Financial  Corporation,  John Hancock Advisers, LLC and MFC Global
Investment Management (U.S.), LLC, agree that the Schedule 13G (Amendment No. 1)
to which this  Agreement  is  attached,  relating to the Common Stock of Modtech
Holdings, Inc., is filed on behalf of each of them.


                                Manulife Financial Corporation


                                By:      /s/ Scott A. Lively
                                Name:    Scott A. Lively
Dated: February 6, 2007         Title:   Attorney in Fact*


                                John Hancock Advisers, LLC


                                By:      /s/ Francis V. Knox Jr.
                                Name:    Francis V. Knox Jr.
Dated: February 6, 2007         Title:   Vice President and Chief Compliance
                                         Officer


                                MFC Global Investment Management (U.S.), LLC


                                By:      /s/ Francis V. Knox Jr.
                                Name:    Francis V. Knox Jr.
Dated: February 6, 2007         Title:   Vice President and Chief Compliance
                                         Officer


* Signed  pursuant to a Power of Attorney dated January 31, 2007 included as an
  Exhibit to Schedule 13G filed with the Securities and Exchange  Commission by
  Manulife Financial Corporation on February 1, 2007.


                                PAGE 8 OF 8 PAGES