Problems with P/Invoke.....Check out ClrSpy
Adam Nathan posted a cool little tool called CLRSpy for finding problems with P/Invoke on the GotDotNet board. We have a problem where we think a Cash Reader Device and Crystal are stepping on each others memory with a Kiosk Framework written in .Net .... I haven't used it yet to see if it solves my problems but it looks like it is worth a look.
-Mathew Nolton