Joomla 1.5.exclude A Directory Rewrite Rule

Hi

I need some advise as I have a joomla 1.5 site.
I also have a separate php application running in a directory /client-area.
I want to adjust the .htacess file so it will not rewrite the client area files.
As you can see I have added this line: RewriteRule ^/client-area(/.*)?$ - [L]
But it will not work it gives me 404 errors.
I would like the client-area to work like the administrator area, where no urls are rewite. Any ideas on the code below.


########## Begin - Joomla! core SEF Section
#
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^/client-area(/.*)?$ - [L]
RewriteCond %{REQUEST_URI} !^/index.php
RewriteCond %{REQUEST_URI} (/|\.php|\.html|\.htm|\.feed|\.pdf|\.raw|/[^.]*)$ [NC]
RewriteRule (.*) index.php
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L]
#
########## End - Joomla! core SEF Section