http://dk.php.net/manual/en/function.mysql-connect.phpc/p fra den første user contributed note:
"For those of you looking to connect to an external mySQL server, for instance to save your client some outrageous charge every month with their current host, this might save you a headache, not to mention the rest of your day...
You will have to modify the Hosts Allow on the mySQL of the external server to allow the connection from your other site. phpMyAdmin has a textfield for this, or simply contact your administrator.
Anyways, lets say you are connecting from the site `yoursite.com`, simply adding `yoursite.com` or `y.o.ur.IP` to the Hosts Allow may not work. You could get an error like:
> Warning: mysql_connect(): Access denied for user: 'yourUser@someOtherSite.com' <
All you need to do is add the `someOtherSite.com` to the Hosts Allow and your all set ... that is to say, you may need to force this error in order to Allow the right host, especially with all the resellers in resellers these days. ;) "