htaccess RewriteRule & htpasswd Clash

[Manny]

I'm currently trying to build an admin CMS and in order to hide querystrings, I have used htaccess to rewrite the URLs into something a little more user friendly. The rewrites work perfectly. However, I want to use htpasswd to protect the directory from outsiders. The code I have at the moment can be found below.

AuthName "Restricted Area"AuthType BasicAuthUserFile /root/to/fileAuthGroupFile /dev/nullrequire valid-user RewriteEngine onRewriteBase /directory/ RewriteRule ^([a-z0-9-]+)/?$ index.php?query=$1 [L]RewriteRule ^([a-z0-9-]+)/([a-z0-9-]+).php$ index.php?query=$1&string=$2 [L]

When I try to use the admin section, I am being presented with this message:[an error occurred while processing this directive] If I remove the first five lines of the code, the CMS works fine, but is not password protected. If I remove everything from line 6 onwards, the htpasswd script kicks in and you are asked to log in with a username and password. What is causing the clash and how can I get the system to work as it should, but with htpasswd protection enabled?