> Is it possible that the problem is related to floating point exceptions?

Hmm.  It's possible, but it's still a bit surprising that the crash occurs at import time rather than when calling one of the cmath functions.  But it's very possible that there are some missing PyFPE_START_PROTECT macros in the cmath source.

BTW, if the problem *is* in cmath, it's likely to also occur with Python 2.7:  that module changed very little between 2.6 and 2.7.