On windows 7, if a Python app is run (under python 2.7.6) and the invoking filename is capitalized differently from the source file itself, a subsequent attempt to use the multiprocessing module to "fork" a process will fail in the "forking" module. This happens because the fopen at line 1559 in import.c (in the "imp" module find_module method) uses the invoking capitalization, rather than the file capitalization and fails to open the file.

The traceback gives lines 380 then 489 in forking.py, but as noted, the problem is in import.c (or in the Python startup, which could convert the capitalization...).