Missing end / - Maybe is simple?

Hi, my .htaccess is setup as:
Options +FollowSymlinks
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !\..+$
RewriteCond %{REQUEST_URI} !/$
RewriteRule (.*) http://www.freedesktopwallpaper.org/$1/ [R=301,L]
RewriteRule ^category/([0-9A-Za-z\+\_\-]+)/$ /categories.php?Category=$1 [nc]
RewriteRule ^category/([0-9A-Za-z\+\_\-]+)/([0-9]+)/$ /categories.php?Category=$1&page=$2 [nc]
RewriteRule ^wallpaper/([0-9A-Za-z\_\-]+)/$ /details.php?Title=$1 [nc]
....

It basically gives the extra / on the end for "category" urls but "wallpaper" urls there is no extra / at the end of the url.

can anyone help as I thought the "RewriteRule (.*) http://www.freedesktopwallpaper.org/$1/ [R=301,L]" code would fix the problem?