Make sure you are adding the correct IP, for example if you are connecting from your local computer to the database, you would put the outside IP address of your local computer.
If you are connecting from another server to the database, you will need to add the outside IP address of the server you are connecting from.
It may be easier to contact live support so they can troubleshoot in real-time.
They are available 24/7 via:
Phone: 888-321-HOST (4678) x2
Chat (there is a link on the top right).