Site index removes "www" from url and files (e.g., '/about') don't work with "www." I have a peculiar problem in that people visit any other page other than the homepage with the "www." before the url they will receive an error.

If they visit the index with the "www." it is removed and whatever links they click will work as it doesn't have the "www." in front.

http://www.domain.com/        - will change to http://domain.com and work fine
http://www.domain.com/about   - will return '404 Not Found'
http://domain.com/about       - will work fine


I have Clean URL's installed (but I can't seem to change any settings in it) and I don't remember touching the .htaccess file.

Any help is much appreciated, thanks.
The following rules remove the www everywhere on your domain.
Put it in .htaccess file:

  RewriteEngine On
  RewriteBase /
  RewriteCond %{HTTP_HOST} ^www.yourdomain.com [NC]
  RewriteRule ^(.*)$ http://yourdomain.com/$1 [L,R=301]