htaccess redirect taking precedence over htaccess basic authentication

I have the following htaccess which redirects front controller commands to a given file....

RewriteEngine on
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f  
RewriteCond %{REQUEST_FILENAME} !-d  
RewriteRule ^([^/]*)$ /index.php?a=$1 [L]

Which sits in the root of the domain and works well, however i have a pass开发者_如何学运维word protected directory at /admin/help/ which contains the following htaccess...

AuthType Basic
AuthName "Your CMS"
AuthUserFile "/path/to/.htpasswd"
require valid-user

The problem is that i'm unable to pull up /admin/help/ in the browser, it simply rewrites to the index.php even though /admin/help/ is a real folder on the server. If i remove the .htaccess from /admin/help/ the folder displays as expected in the browser so i presume i'm missing something from this 2nd .htaccess file however i can't figure out what it is, so any suggestions would be much appreciated?

Thanks