I'm having the following issue on a host using Apache 2.2.22 + PHP 5.4.0

I need to provide the file /home/server1/htdocs/admin/contents.php when a user makes the request: http://server1/admin/contents, but I obtain this message on the server error_log.

Negotiation: discovered file(s) matching request: /home/server1/htdocs/admin/contents (None could be negotiated)

Notice that I have mod_negotiation enabled and MultiViews among the options for the related virtualhost:

<Directory "/home/server1/htdocs">
    Options Indexes Includes FollowSymLinks MultiViews
    Order allow,deny
    Allow from all
    AllowOverride All
</Directory>

I also use mod_rewrite, with the following .htaccess rules: RewriteEngine On RewriteBase /

    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^([^\./]*)$ index.php?t=$1 [L]
</IfModule>

It seems very strange, but on the same box with PHP 5.3.6 it used to work correctly. I'm just trying an upgrade to PHP 5.4.0, but I cannot solve this negotiation issue. Any idea on why Apache cannot match contents.php when asking for content (which should be what mod_negotiation is supposed to do)?