Playonline Viewer: UCS-5004Follow

So me and my father just verified our credit card information, at pretty
much the last step of the process of registering.

Then, suddenly, an error message appears:

UCS-5004

The server is busy
Please try again later

--
We then hit 'back' and hit 'submit' again. Still recieve that same darn error message.

Anyone have a clue on a fix, or an explanation or something?

Also, after so many tries it will lock out (or in other words not accept) the card for awhile...