Any way to trace unhandled exceptions easily?

I try to use try catch statements everywhere appropriate, but sadly there are places in my code that are unhanded.
The problem is that once I get to one of these exceptions, all I get is Unhandled exception and the code reference is [External code]. I know the general area of code that it is occurring in but the crash is part of a race condition, and only intermittent so locating the place is going to be difficult. If I could trace the stack I could find it easier.

Any ideas?