.htaccess authentication does not stop page loading

[eluser]gojo[/eluser]
This worked for my virtually the same problem

Code:

AuthName "bobby"
AuthUserFile "/location to password here/passwd"
AuthType Basic
require valid-user

RewriteEngine on
RewriteCond %{remote_user} !^$ [nc]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule .* index.php/$0 [PT,L]