If that doesn't solve the problem, check the user's host. Using Query Browser or the command line client, while connected as root, issue the following command:
SELECT user, host FROM mysql.user WHERE user = 'theUserYouCreated';
Check the `host` field. If it is set to the wildcard "%," your user should be able to connect from anywhere. If it is set to "localhost," your user can only connect from the server on which MySQL is running. Use the GRANT statement to give user access from "%."
This was first published in September 2006