[mod_python] mod_python and MultiViews

I have mod_python 3.0 running with Apache 2.0.43.  Using the publisher 
handler, a request for "/foo.py/bar" resolves correctly.  If I turn on 
MultiViews in httpd.conf and use the URL "/foo/bar", it fails.  In the 
error log, I get:

   Negotiation: discovered file(s) matching request: /apache2/htdocs/foo
   (None could be negotiated).

This is on an OpenBSD system, but the same thing works fine on Mac OS 
X.  Anyone know what I'm missing to convince Apache that it should 
accept foo.py?

thx