SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

                             ____________________

                                 SCHEDULE 13G
                                (Rule 13d-102)

            INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
          TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED
                           PURSUANT TO RULE 13d-2(b)
                              (Amendment No. 6)*

                                MOBILE MINI INC
          ___________________________________________________________
                               (Name of Issuer)


                                 COMMON STOCK
          ___________________________________________________________
                        (Title of Class of Securities)


                                   60740F105
                        ______________________________
                                (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 disclosures provided in a prior cover page.

      The  information  required  on the  remainder  of this 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.)














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CUSIP No 60740F105              13G                Page 2 of 5
                                                      Pages
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   1    NAMES OF REPORTING PERSONS
        I.R.S.  IDENTIFICATION  NO. OF ABOVE  PERSONS  (ENTITIES
        ONLY):

        Columbia Wanger Asset Management, L.P.
        04-3519872

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   2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
        (a) [ ]
                                                  (b) [ ]
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   3    SEC USE ONLY


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   4    CITIZENSHIP OR PLACE OF ORGANIZATION

                                                        Delaware
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                 5  SOLE VOTING POWER
   NUMBER OF
     SHARES
  BENEFICIALLY
 OWNED BY EACH
   REPORTING
  PERSON WITH

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                 6  SHARED VOTING POWER
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                 7  SOLE DISPOSITIVE POWER
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                 8  SHARED DISPOSITIVE POWER
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   9    AGGREGATE  AMOUNT  BENEFICIALLY  OWNED BY EACH REPORTING
        PERSON

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  10    CHECK  IF  THE  AGGREGATE  AMOUNT  IN ROW  (9)  EXCLUDES
        CERTAIN SHARES*

                                                            [  ]
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  11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                                   Less than 5% (closing filing)
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  12    TYPE OF REPORTING PERSON*

                                                              IA
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                     *SEE INSTRUCTIONS BEFORE FILLING OUT!










Item 1(a). Name of Issuer:

           MOBILE MINI INC

Item 1(b). Address of Issuer's Principal Executive Offices:

           7420 South Kyrene Road
           Suite 101
           Tempe, AZ 85283

Item 2(a). Name of Person Filing:

           Columbia Wanger Asset Management, L.P.

Item 2(b). Address of Principal Business Office or, if None, Residence:

           227 West Monroe Street, Suite 3000, Chicago, IL  60606.

Item 2(c). Citizenship:

           Delaware

Item 2(d). Title of Class of Securities:

           Common Stock

Item 2(e). CUSIP Number:

           60740F105

Item 3.    If This Statement is Filed  Pursuant to Rule  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
           Exchange Act.
           (b)  [  ] Bank as defined in Section 3(a)(6) of the Exchange Act.
           (c)  [ ]  Insurance  company as defined in  Section 3(a)(19)  of the
                Exchange Act.
           (d)  [ ]  Investment  company  registered  under  Section 8  of  the
                Investment Company Act.
           (e)  [X]    An    investment     adviser    in    accordance    with
           Rule 13d-1(b)(1)(ii)(E).
           (f)  [ ] An employee  benefit plan or endowment  fund in  accordance
                with Rule 13d-1(b)(1)(ii)(F).
           (g)  [ ] A parent  holding  company or control  person in accordance
                with Rule 13d-1(b)(1)(ii)(G).
           (h)  [ ] A savings  association  as defined in  Section 3(b)  of the
                Federal Deposit Insurance Act.
           (i)  [ ] A church plan that is excluded  from the  definition  of an
                investment  company  under Section  3(c)(14) of the  Investment
                Company Act.
           (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.  [  ]

Item 4.    Ownership:

           With respect to the  beneficial  ownership of the reporting  person,
           see Items 5  through  11 of the cover  pages to this  Schedule  13G,
           which are incorporated herein by reference.

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:

           Not applicable.

Item 7.    Identification  and  Classification of the Subsidiary Which Acquired
           the  Security  Being  Reported on by the Parent  Holding  Company or
           Control Person:

           With respect to Subsidiary  Identification and  Classification,  see
           Items 5 through 11 of the cover pages to this  Schedule  13G,  which
           are incorporated herein by reference.

Item 8.    Identification and Classification of Members of the Group:

           Not applicable.

Item 9.    Notice of Dissolution of Group:

           Not applicable.







Item 10.   Certification:

           By signing  below each of the  undersigned  certifies  that,  to the
           best of such  undersigned's  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 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.

                                      SIGNATURE

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

Dated:     January 8, 2007

                                  Columbia Wanger Asset Management, L.P.

                                  By:     /s/ Bruce H. Lauer
                                    _____________________
                                  Bruce H. Lauer,
                                  Senior Vice President and Secretary,
                                  WAM Acquisition GP, Inc., General Partner