URL Problem when without slash

[eluser]reaktivo[/eluser]
Hi all, I have a problem when trying to access the CI root ... the url is: http://grupofema.com/admin/ , where admin is the codeigniter folder, so the problem is that when i try to access it using http://grupofema.com/admin (without the last slash) it gives me a

Bad Request. Your browser sent a request that this server could not understand.

message, my .htaccess is as follows:

Code:

SecFilterEngine Off
SecFilterScanPOST Off
RewriteEngine On
RewriteCond $1 !^(index\.php|images|imgs|js|css|files)
RewriteRule ^(.+)$ index.php?$1 [L]

(i need the secfilter's off so i can upload files)...
thanks for any help.