Can't register after purchasing Winamp 5.54
 

I have just purchased Winamp 5.54 and paid with my credit card. After installing the software and entering my name and registration key, I get a message saying "Invalid registration key". I then tried to follow the customer services link from the web site but this gives a blank page with an error.
This is really annoying as I have purchased the software and can't use it, at least not in the Pro version.
I know this forum might not be the right place to ask for help, but I can't find anywhere else on this web site to contact the right people, especially as the customer services link does not work.

I have a Windows Vista Home Premium machine, Winamp 5.54 and a purchased Registration name/key that doesn't work!!

Please help.