It's good to see a well thought out and non noobish post for once...
Are you able to connect to your MySQL server from any other scripts/clients?
Is it a remote connection or a local one?
Post your connect line(s) (obviously removing all passwords :P).
I'm unfamiliar with the frontend you're using, but do you know PHP well enough to put in an line like this after the mysql_connect()?
Code:
echo "\n\n<br /><b>Error: </b>".mysql_error()."<br />\n\n";
Although none of these will fix your problem, they will all help work out the problem :).
-nfsnobody