[mod_python] Failed to acquire global mutex lock on OS X 10.4.1

Hello all,

I'm trying to use mod_python on a Mac and ran into a problem when
creating a mod_python.Session instance.  When I do:

from mod_python import apache, Session

def handler(req):
    s = Session.Session(req)
    [...]

I get the following error:

File "/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site-packages/mod_python/Session.py",
line 215, in lock
    _apache._global_lock(self._req.server, self._sid)

ValueError: Failed to acquire global mutex lock

I'm using the following software:

httpd 2.0.54 (./configure --prefix=/berto --enable-dav --enable-dav-fs
--enable-cgi && make && make install)
mod_python 3.1.4 (./configure --prefix=/berto
--with-apxs=/berto/bin/apxs --with-python=/usr/bin/python && make &&
make install)
python 2.3.5 (OS X Tiger default)

Any suggestions would be greatly appreciated.

Thanks in advance!

-Roberto.