[mod_python] AddHandler/SetHandler ignored by apache

Hello,

my problem is simple, and might not even be related to mod_python but to
apache2:
Instead of seeing the output of my scripts, apache2 returns the contents
of the script itself.

I have this setup:
Apache/2.0.48 (Debian GNU/Linux) mod_python/3.0.4 Python/2.3.3
The contents of /etc/apache2/sites-enabled/default are appended at the
end of this mail.

This is what I tried:
http://www.modpython.org/live/current/doc-html/inst-testing.html

All I get is the source of mptest.py, so apache2 doesn't seem to call
mod_python at all. What am I missing?

Thanks a lot for any hints!

Regards,
Marc

Contents of /etc/apache2/sites-enabled/default:

NameVirtualHost *:80
<VirtualHost *:80>
ServerAdmin webmaster at localhost

DocumentRoot /home/www/mp/
<Directory /home/www/mp>
 Options Indexes FollowSymLinks MultiViews
 AllowOverride FileInfo
 Order allow,deny
 allow from all
</Directory>

<Directory /home/www/mp>
 AddHandler mod_python .py
 PythonHandler mptest

 PythonDebug On
</Directory>

ErrorLog /var/log/apache2/error.log

LogLevel debug

CustomLog /var/log/apache2/access.log combined
ServerSignature On

</VirtualHost>