[mod_python] leopard - no interpret

text is dumped to web page instead of being interpreted.

using apple python and apache2 on leopard macbook pro:
mod_python/3.3.1 Python/2.5.1 configured
i built mod_python with -arch i386 and -arch x86-64 in the mod_python  
src/makefile - no problem.

in httpd.conf i have:
<Directory "/Library/Webserver/Documents">
     AddHandler mod_python .py
     PythonHandler mod_python.publisher
     PythonDebug On
</Directory>


my test script has:
from mod_python import apache

def hello(req):
   req.content_type = "text/plain"
   req.write("Hollow Earth")
   return

actually, when i try localhost/mptest.py/hello, i get 'file not found' -
going to localhost/mptest.py gives me the text dump of the file.

any suggestions?