[mod_python] Session unable to acquire mutex lock?

Hi,

I'm a newbie to mod_python so forgive me if this is a terribly obvious
question (I've looked through the archives without much success).

I'm trying to use sessions.  Right now I have a slightly modified version
of mptest.py as follows (it doesn't make sense, but it does show my
problem):

    from mod_python import apache, Session
    import sys

    def handler(req):
        req.content_type = 'text/plain'
        req.write("Creating...\n")
        sess = Session.Session(req)
        req.write("Hello World!")
        return apache.OK

When I run it, I see:

     Mod_python error: "PythonHandler mptest"

     Traceback (most recent call last):

       File "/usr/lib/python2.3/site-packages/mod_python/apache.py", line 338, in HandlerDispatch
         result = object(req)

       File "/srv/www/htdocs/test/mptest.py", line 7, in handler
         sess = Session.Session(req)

       File "/usr/lib/python2.3/site-packages/mod_python/Session.py", line 411, in Session
         timeout=timeout)

       File "/usr/lib/python2.3/site-packages/mod_python/Session.py", line 316, in __init__
         secret=secret, timeout=timeout)

       File "/usr/lib/python2.3/site-packages/mod_python/Session.py", line 170, in __init__
         self.lock()                 # lock new sid

       File "/usr/lib/python2.3/site-packages/mod_python/Session.py", line 241, in lock
         _apache._global_lock(self._req.server, self._sid)

     ValueError: Failed to acquire global mutex lock


What am I doing wrong here?!

Thanks for any suggestions,
Russell.

PS:

I'm running on SuSE 9.0 Linux.

Python reports version "Python 2.3+ (#1, Sep 23 2003, 23:07:16)".

>From the Apache error page: 
    Apache/2.0.48 (Linux/SuSE), 
    mod_python/3.1.2b 
    Python/2.3+.

The only glitch I had in building mod_python was that I needed to specify 
    ./configure --with-apxs=/usr/sbin/apxs2

rather than just refering to apxs.

My apache configuration is (from the tutorial):
<Directory /srv/www/htdocs/test> 
  AddHandler python-program .py
  PythonHandler mptest 
  PythonDebug On 
</Directory>