cannot load default controller

hi,
my codeigniter is placed in a subfolder.
when im trying to load it.

www.website.com/ci <-- it gives me 404 error
but when i did this
www.website.com/ci/welcome <-- it display the page.

.htaccess

Code:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L] 
</IfModule>

thanks