Problem Connecting to MP

[Herpus Derpus]

I recently got a GS account to play M2TW which I got an unopened copy off Amazon(Gold Edition).

I put in the activation code, and after playing SP for a few days and getting used to new engine, I tried to log onto MP and got the message "Failed to Logon Logon Failed--Invalid CD-Key" if this was a problem entering CD key, where do I change it, if not is there a fix to this?

[irishron]

Ask Gamespy support is all I know.