Why does the mptest.py source get shown instead of executed?

Apache/2.2.11 (Win32) mod_python/3.3.1 Python/2.5.2

The URL I tried using was: http://localhost/test/mptest.py

httpd.conf directives:
----------------------------------------
DocumentRoot "C:/Program Files/Apache Software Foundation/Apache2.2/htdocs"

<Directory /test>
  AddHandler mod_python .py
  PythonHandler mptest
  PythonDebug On
</Directory>
----------------------------------------

Under .../htdocs, I have "test" as a directory, containing this file:

----------------------------------------
from mod_python import apache

def handler( req ) :
  req.content_type = 'text/plain'
  req.write( "Hello World!" )
  return apache.OK
----------------------------------------

I followed the installation instructions found here:

http://www.modpython.org/live/current/doc-html/installation.html

and testing instructions found here:

http://www.modpython.org/live/current/doc-html/inst-testing.html

and the troubleshooting instructions found here:

http://www.modpython.org/live/current/doc-html/inst-trouble.html

As part of the troubleshooting, I added this directive to my httpd.conf:

----------------------------------------
<Location /mpinfo>
  SetHandler mod_python
  PythonHandler mod_python.testhandler
</Location>
----------------------------------------

I was able to access that page using:  http://localhost/mpinfo
and it showed the page in all its glory.

What am I missing?