Sounds to me like you have a memory problem; one common symptom of those types of problems is that they work fine in Debug mode but not in Release mode, or vice versa. Check to make certain you aren't trying to use uninitialized values anywhere.

Also, if you add logging to your program, then you'll have a better idea of what it's doing even if it exits. My programs generate copious logs; while I can always remove them later, they're very helpful during the development process.