how to debug possible heap corruption?
===

VS2008, C. Also using some pre-built libraries.
When I step through my code in the debugger and over the library functions being called, I get this:

> HEAP[unit_test.exe]: Heap missing last entry in committed range near
> 35c70 Windows has triggered a breakpoint in unit_test.exe.
> 
> This may be due to a corruption of the heap, which indicates a bug in
> unit_test.exe or any of the DLLs it has loaded.
> 
> This may also be due to the user pressing F12 while unit_test.exe has
> focus.
> 
> The output window may have more diagnostic information.

Any ideas on how to debug this?
