In Mambo the default installation had a problem where when we click on "Preview" on a website page it would ask for a login and wouldn't display your page.  This is a know error in the code and here is the instructions on how to correct this issue.

Edit file /mambo/administrator/includes/auth.php, line 22:

session_name( 'mosadmin' );

change to

session_name( md5( $mosConfig_live_site ) );