delphi - How to track down tricky memory leak with fastMM?

Question

After upgrading a project from Delphi 2007 to Delphi 2009 I'm getting an Unknown memory leak, so far I've been tryin to track it down using fastMM, here is what fastMM stack trace reports:

A memory block has been leaked. The size is: 20

This block was allocated by thread 0x111C, and the stack trace (return addresses) 
  at the time was:
40339E [System.pas][System][@GetMem][3412] 534873 [crtl][_malloc]
56D1C4 [canex.cpp][MidasLib][DllGetDataSnapClassObject][3918]
56D316 [canex.cpp][MidasLib][DllGetDataSnapClassObject][3961]
56D5EE [canex.cpp][MidasLib][DllGetDataSnapClassObject][4085]
562D48 [DBCommon.pas][DBCommon][TFilterExpr.PutExprNode][1583]
408E46 [System.pas][System][DynArraySetLength][20464]
56D5EE [canex.cpp][MidasLib][DllGetDataSnapClassObject][4085]
408E92 [System.pas][System][@DynArraySetLength][20486]
528C1B [Forms.pas][Forms][TCustomForm.DoCreate][3260]
171A1A [GetRawStackTrace]

The block is currently used for an object of class: Unknown

The allocation number is: 302844

And sometimes I get this:

A memory block has been leaked. The size is: 20

This block was allocated by thread 0x111C, and the stack trace (return addresses) 
  at the time was:
40339E [System.pas][System][@GetMem][3412]
534873 [crtl][_malloc]
56D1C4 [canex.cpp][MidasLib][DllGetDataSnapClassObject][3918]
56D316 [canex.cpp][MidasLib][DllGetDataSnapClassObject][3961]
77DC921A [RtlAnsiStringToUnicodeString]
56D5EE [canex.cpp][MidasLib][DllGetDataSnapClassObject][4085]
7726B8F5 [GetProcAddress]
7726B907 [GetProcAddress]
589B1E [ossrv.cpp][MidasLib][DllGetDataSnapClassObject][3163]
56D5EE [canex.cpp][MidasLib][DllGetDataSnapClassObject][4085]
408E92 [System.pas][System][@DynArraySetLength][20486]

The block is currently used for an object of class: Unknown

Is there some better way to figure out what really is causing the Memory leak?

Answer 1

This memory leak was being caused by a Delphi bug, QC #67709

It was fixed by the last Delphi 2009 update, no wonder I wasn't able to fix it.