My application runs fine in the emulator, but I constantly get random, unexplainable crashes when running on an actual iPhone. What options are available to me as far as debugging?

I've found the crash reports in XCode Device Logs, but all I can tell is that the exception type is "EXC_CRASH (SIGABRT)" - and I don't even really know what that tells me.

Reproducing the problem has been a nightmare, since the crashes seem to behave differently whenever I reinstall the app. I'm using Titanium 1.3.2 and iPhone SDK 4.0