Yup. Happened to me - see the OOP / DarkGDK thread. AndrewT took my code (tested and 100%) on XP! and same thing.
I asked him to try in Visual Studio and send me a screenie. It was blowing up at a WRITEMEMBLOCK command.
I wonder if its a bug. I had him comment out that code, and it blew up (I think..check that thread) at another memblock command.
Almost as if the ENDIAN, BYTE ALIGNMENT, or something hosed it really bad OR WORSE!!! TGC has code internal that tried to work one way under VISTA and another way under XP - A vulnerable thing to do if you ask me...
I tend to lean towards memblock bug regardless of the hows and whys... until I have more info anyway... that's my story ... and I'm sticking to IT!