Internet Explorer 9 Silverlight 4 memory leak

We are streaming video from a ashx implementing IHttpAsyncHandler to our Silverlight client.

On the clientside the async handler is getting use in a implementation of MediaStreamSource.

It all runs fine in latest Firefox, chrome and also in Internet Explorer 8.

But in Internet Explorer 9 we see a memory leak. I have been using umdh to debug the memory and have found a callstack that used 127mb between to dumps of the memory. So i think i have narrowed it down to this callstack.

But now i don't know now to continue with my debugging. Here is the umdh info:

First the compare between first run and second

+ 117440512 ( 134217712 - 16777200)      1 allocs   BackTrace121282BC
+       0 (      1 -      1)    BackTrace121282BC   allocations

ntdll!RtlAllocateHeap+00000274
npctrl!???+00000000 : 56FE1A65
npctrl!DllCanUnloadNow+000157F0
npctrl!???+00000000 : 56FF477E
npctrl!???+00000000 : 56FF48D5
urlmon!CBSCHolder::OnDataAvailable+0000003A
urlmon!CBinding::CallOnDataAvailable+0000002B
urlmon!CBinding::OnDataNotification+000000D7
urlmon!CBinding::OnTransNotification+000001DB
urlmon!CBinding::ReportData+00000085
urlmon!COInetProt::ReportData+0000006E
mscorie!CorFltr::ReportData+0000002B
urlmon!CTransaction::DispatchReport+0000037A
urlmon!CTransaction::OnINetCallback+000000DB
urlmon!TransactionWndProc+00000028
USER32!InternalCallWinProc+00000023
USER32!UserCallWinProcCheckWow+00000109
USER32!DispatchMessageWorker+000003BC
USER32!DispatchMessageW+0000000F
IEFRAME!CTabWindow::_TabWindowThreadProc+00000722
IEFRAME!LCIETab_ThreadProc+00000317
iertutil!CIsoScope::RegisterThread+000000AB
IEFRAME!Detour_DefWindowProcA+0000006C
kernel32!BaseThreadInitThunk+0000000E
ntdll!__RtlUserThreadStart+00000070
ntdll!_RtlUserThreadStart+0000001B

The second run callstack

+ 7fffff0 ( 7fffff0 -     0)      1 allocs  BackTrace121282BC
+       1 (     1 -     0)  BackTrace121282BC   allocations

ntdll!RtlAllocateHeap+00000274
npctrl!???+00000000 : 56FE1A65
npctrl!DllCanUnloadNow+000157F0
npctrl!???+00000000 : 56FF477E
npctrl!???+00000000 : 56FF48D5
urlmon!CBSCHolder::OnDataAvailable+0000003A
urlmon!CBinding::CallOnDataAvailable+0000002B
urlmon!CBinding::OnDataNotification+000000D7
urlmon!CBinding::OnTransNotification+000001DB
urlmon!CBinding::ReportData+00000085
urlmon!COInetProt::ReportData+0000006E
mscorie!CorFltr::ReportData+0000002B
urlmon!CTransaction::DispatchReport+0000037A
urlmon!CTransaction::OnINetCallback+000000DB
urlmon!TransactionWndProc+00000028
USER32!InternalCallWinProc+00000023
USER32!UserCallWinProcCheckWow+00000109
USER32!DispatchMessageWorker+000003BC
USER32!DispatchMessageW+0000000F
IEFRAME!CTabWindow::_TabWindowThreadProc+00000722
IEFRAME!LCIETab_ThreadProc+00000317
iertutil!CIsoScope::RegisterThread+000000AB
IEFRAME!Detour_DefWindowProcA+0000006C
kernel32!BaseThreadInitThunk+0000000E
ntdll!__RtlUserThreadStart+00000070
ntdll!_RtlUserThreadStart+0000001B

Have you already solved your problem?

Have you checked SL memory debugging tips such as:

http://radheyv.blogspot.cz/2011/04/detecting-memory-leaks-in-silverlight.html#!/2011/04/detecting-memory-leaks-in-silverlight.html

http://blogs.msdn.com/b/slperf/archive/2010/08/19/analyzing-silverlight-memory-usage-part-1-obtaining-measurements.aspx

http://dllshepherdnotes.blogspot.cz/2011/02/silverlight-memory-leak-part-4.html#!/2011/02/silverlight-memory-leak-part-4.html

http://www.dllshepherd.net/2011/02/silverlight-memory-leak-part-2.html