Sound problem with PMDG744X

Hello PMDGI have a problem with the 744X. Here is the detail with problem report from MS Vista 64bit with SP1.My 744x is 2.1(with the latest SP)It seemed to be a sound problem. This happened after a long time flight(Not happened during loading the plane), usually during the final approach, like when I disconnect the A/T or A/P. Then the whole FSX will freeze.My FSX with SP2, running without DX10 Preview.Would you please take a look and help me to find the solution?Problem signature: Problem Event Name: APPCRASH Application Name: fsx.exe Application Version: 10.0.61472.0 Application Timestamp: 475e17d3 Fault Module Name: PMDGSounds.dll Fault Module Version: 10.0.61355.40 Fault Module Timestamp: 483af582 Exception Code: c0000005 Exception Offset: 0000eb12 OS Version: 6.0.6001.2.1.0.256.1 Locale ID: 1033If you need any further detail please let me know.