How to redirect from www.domain.com to domain.com?

This should do it. The problem is that it looks pretty much like what you already have. When you type http://domain.com in your browser, does it work? Or does it redirect to somewhere else?

RewriteEngine on
RewriteCond %{HTTP_HOST} ^www\.domain\.com
RewriteRule ^(.*)$ http://domain.com$1 [R=permanent,L]