All site-packages were compiled against python 2.6.1, and python was
upgraded later to 2.6.2 (but upon running a make install with python
2.6.2, it seemed to recompile site-packages on a byte-code level).

And no, there is still segfaults without optimizations, I've tried at
-O2 -O and -O0 ( -O0 being no optimization). Judging by the invalid read
always being on 0x58, and the line of assembly accessing 0x58 offset
from a register, tstate->frame must be being initilized to NULL (or
always being corrupted to point to other NULL data)

The compiler used is gcc version 4.1.2 20071124 (Red Hat 4.1.2-42)

The setup we are using is 8-core xeon 64-bit servers. (We have about 14
of these, Centos based systems, all are experiencing the segfaults).