Hi Guys,
If you preregistered on the Beta server and received a Beta Key, you should be able to login in the top right by inserting your login and password. A new window will spawn asking for your Betakey then. If you did not pre-register and received a Beta Key, use the registration field on the left to enter the login, password and betakey.
Pitfall:
If you pre-registered, with a certain name, AND use the registration on the left with the same name, to enter the game with a BetaKey (which is only for registration), you will receive an invalid name error, as the name is technically already on our server. Hope this clarifies the issue a bit.
@ Preto, In your case it was faster to pass you a new key as it was sure that this would indeed solve your issue. This is a last resort and not the first step of the troubleshooting process.
Thank you for your comments.