Here is the output of python -v during "import _multiprocessing". Maybe
this gives someone a clue?

>>> import _multiprocessing
dlopen("/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/_multiprocessing.so",
2);
# /Users/guido/p3/Lib/pickle.pyc matches /Users/guido/p3/Lib/pickle.py
import pickle # precompiled from /Users/guido/p3/Lib/pickle.pyc
import marshal # builtin
# /Users/guido/p3/Lib/struct.pyc matches /Users/guido/p3/Lib/struct.py
import struct # precompiled from /Users/guido/p3/Lib/struct.pyc
dlopen("/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/_struct.so", 2);
import _struct # dynamically loaded from
/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/_struct.so
dlopen("/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/binascii.so", 2);
import binascii # dynamically loaded from
/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/binascii.so
dlopen("/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/_pickle.so", 2);
import _pickle # dynamically loaded from
/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/_pickle.so
import multiprocessing # directory /Users/guido/p3/Lib/multiprocessing
# /Users/guido/p3/Lib/multiprocessing/__init__.pyc matches
/Users/guido/p3/Lib/multiprocessing/__init__.py
import multiprocessing # precompiled from
/Users/guido/p3/Lib/multiprocessing/__init__.pyc
# /Users/guido/p3/Lib/multiprocessing/process.pyc matches
/Users/guido/p3/Lib/multiprocessing/process.py
import multiprocessing.process # precompiled from
/Users/guido/p3/Lib/multiprocessing/process.pyc
dlopen("/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/itertools.so", 2);
import itertools # dynamically loaded from
/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/itertools.so
import _multiprocessing # dynamically loaded from
/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/_multiprocessing.so
import _multiprocessing # dynamically loaded from
/Users/guido/p3/build/lib.macosx-10.3-i386-3.0/_multiprocessing.so
>>>