.htaccess rewrites one url, not the other

Question

I've got this set of .htaccess rewrites set up (Zend Framework default rewrite rules):

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^.*$ index.php [NC,L]

My DocumentRoot folder contains only .htaccess and index.php, nothing else.

The rewrite rules should send all requests to non-existing files through index.php. This happens for /herp/derp/ (wheter a controller exists or not) , but not for /index/herp/ or any other url starting with /index/.

All /index/* urls are routed to the 404 page of apache, all other urls do work.

How should I fix this?

Answer 1

Turned out that MultiViews do this. Still not sure why :P