Without seeing the code, it's hard to tell. The most likely causes for "bus errors" (or segfaults) are external libraries linked into Perl which cause memory corruption. So your best bet is to stepwise remove all modules that use external libraries until the error goes away, and then add them in again, one by one, to eliminate the offending external library.

Another possibility for intermittent segfaults is faulty hardware, like RAM that gets too hot or something similar.