See following example (that's what we know): 
# Importing 2.1 module with Python 2.3 
frank@theta:~> python 
Python 2.3+ (#1, Jan  7 2004, 09:17:35) 
[GCC 3.3.1 (SuSE Linux)] on linux2 
Type "help", "copyright", "credits" or "license" for more 
information. 
>>> import sys 
>>> sys.path.insert(0, '/usr/lib/python2.1/lib-dynload') 
>>> import cmath 
__main__:1: RuntimeWarning: Python C API version mismatch 
for module cmath: This Python has API version 1012, module 
cmath has version 1010. 
>>> 
================================== 
Ignoring this warning works without problem, but raising an 
exception will lead to segmentation fault: 
# Starting python with warnings turned into exceptions 
frank@theta:~> python -W error 
Python 2.3+ (#1, Jan  7 2004, 09:17:35) 
[GCC 3.3.1 (SuSE Linux)] on linux2 
Type "help", "copyright", "credits" or "license" for more 
information. 
>>> import sys 
>>> sys.path.insert(0, '/usr/lib/python2.1/lib-dynload') 
>>> import cmath 
Speicherzugriffsfehler (seg fault)