need debugging help

hello,
I've got a really big script, where i have callbacks in other functions, so that it lost any linear structure.
The problem is, that i'm getting random crashes (in some situations more than in others, but not exclusivly there) in the script and i have no idea how i can find the crashes cause.
the engine isn't really helpful here. it doesn't give me any error message, scriptfile or line number. it just crashes.

What are the best ways to get nearer to such a problem? maybe with some kind of external tools? or is there another possibility to get the linenumber it was caused by?

Thank you for you suggestions =)
Scorpion

Oh this sounds like it could be a PITA.

Are you sure you don't have a reproducible case for the crash? It's just random all the time?

well i have newton as a physikengine and my guess is that something is going wrong with the collision or at least something that got changed after collision happened, but because there are every frame a few collisions it's hard to tell if it is so or not.