[RESOLVED] Acess violation in multithread prgm on closing DlgBox

I have done a programme to solve Rubic cube using 2 phase algorithm (1340 lines of code).
It works fine on running in Debug mode. Fine! When I close the Dialog box finally,
it ends up in access violation. (in stead of Closing, you 'Stop Debugging', it exits OK). I feel it may not be due to threading (used 3 threads), since absolutely no problem while running (about 150 problems solved in less than 1 hour w.o any bugs).
I do not know How to debug this access vilation and fix the error. Can any Guru guide me /help.
I can give more details as required.
raghavan


RESOLVED:
I HAD GIVEN AN OLD DLG.H FILE IN APP..CPP FILE WHICH CAUSED ALL THE PROBLEMS. NOW PROBLEM IS RESOLVED.
raghavan