www. links broken

With this plugin activated (and user has correct permissions ie. should be able to access).. if they use:

http://mydomain.com/link/ They reach the correct page.

However if instead they use:

http://www.mydomain.com/link/ They are instead redirected to the redirection page.

Seems the ‘www’ part is a problem.

http://wordpress.org/plugins/wordpress-access-control/