**Exhibit
      31.2**




**CERTIFICATION**




I,
      A.
      Clay Leighton, certify that:




1.
      I have
      reviewed this annual report on Form 10-K of Sonic Solutions;




2.
      Based
      on my knowledge, this annual report does not contain any untrue statement of
      a
      material fact or omit to state a material fact necessary to make the statements
      made, in light of the circumstances under which such statements were made,
      not
      misleading with respect to the period covered by this annual report;




3.
      Based
      on my knowledge, the financial statements, and other financial information
      included in this annual report, fairly present in all material respects the
      financial condition, results of operations and cash flows of the registrant
      as
      of, and for, the periods presented in this annual report;




4.
      The
      registrant’s other certifying officer and I are responsible for establishing and
      maintaining disclosure controls and procedures (as defined in Exchange Act
      Rules
      13a-15(e) and 15d-15(e)) and internal control over financial reporting (as
      defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and
      we
      have:




a)
      Designed such disclosure controls and procedures, or caused such disclosure
      controls and procedures to be designed under our supervision, to ensure that
      material information relating to the registrant, including its consolidated
      subsidiaries, is made known to us by others within those entities, particularly
      during the period in which this annual report is being prepared;




b)
      Designed such internal control over financial reporting, or caused such internal
      control over financial reporting to be designed under our supervision, to
      provide reasonable assurance regarding the reliability of financial reporting
      and the preparation of financial statements for external purposes in accordance
      with generally accepted accounting principles;




c)
      Evaluated the effectiveness of the registrant’s disclosure controls and
      procedures and presented in this annual report to our conclusions about the
      effectiveness of the disclosure controls and procedures, as of the end of the
      period covered by this report based on such evaluation; and




d)
      Disclosed in this annual report any change in the registrant’s internal control
      over financial reporting that occurred during the registrant’s most recent
      fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual
      report) that has materially affected, or is reasonably likely to materially
      affect, the registrant’s internal control over financial reporting; and




5.
      The
      registrant’s other certifying officer and I have disclosed, based on our most
      recent evaluation of internal control over financial reporting, to the
      registrant’s auditors and the audit committee of registrant’s board of directors
      (or persons performing the equivalent functions):




a)
      All
      significant deficiencies and material weaknesses in the design or operation
      of
      internal control over financial reporting which are reasonably likely to
      adversely affect the registrant’s ability to record, process, summarize and
      report financial information; and




b)
      Any
      fraud, whether or not material, that involves management or other employees
      who
      have a significant role in the registrant’s internal controls and control over
      financial reporting.




Date:
              June 14, 2006
            By:
            /s/ A.
              Clay
              LeightonA.
              Clay LeightonExecutive
              Vice
              President and Chief Financial Officer