I've been testing mod_python 3.2.x betas as requested by the developers on their mailing list. Unfortunately there seems to be some subtle memory-related but that only occurs on FreeBSD (or at least FreeBSD the way I normally install it along with Apache and Python).
Made some mention of it here
and an almost identical problem is reported for MacOSX,
even down to the value
0x58 being at the top of the backtrace.
Did a lot of poking around the core with gdb and browsing of the mod_python and Apache sourcecode, but never quite saw where the problem could be. Took another approach and started stripping down the big mod_python testsuite, and found that the test that was failing ran fine by itself, but when it ran after another test for handling large file uploads - then it would crash.
So I suspect there's a problem in a whole different area of mod_python, that's screwing something up in memory that doesn't trigger a segfault til later during the connectionhandler test. My latest post to the list covers some of that.