I'm not quite sure what the problem is but when u granted access to the user did u do...
grant SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER on mydatabase.* to username@localhost identified by 'password';
AND
grant SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER on mydatabase.* to username@% identified by 'password';
and then flushed the privileges? I remember that u need to do both to allow access.
If this doesn't fix it, exactly wot error message are u getting from the MySQL server?
Mitchell