Useful info from crash?

Hi, I have a ghc program that appears to be causing a memory error (either segfaulting or tripping up X and killing my session). The program is rather disorganised, so I'm trying to reduce it to something more compact before submitting a report. Is there anything that would help me locate the source of the error so I know what to include/exclude, apart from trial and error? The error occured with both ghc5 (whatever is in debian stable) and 6.0.1 (again from debian package). Thanks, Andrew -- http://www.acooke.org/andrew