Email alias and game center

I thought it might be nice to use a separate email alias (in my iCloud mail setup) for the Apple game center. I was never a mobile me user, but when Apple started iCloud, I setup an Apple email account for the cloud. We can create up to 3 email alias's. So, I created one. I tested it by sending an email using the alias, and having someone send me one at that alias. I can receive these on my iPad/iPhone and see them in my mail at cloud.com from my Mac.

I cannot use the alias as a contact address in the game center, it will not send a verification email. Following some suggestions regarding our Apple ID account, I tried to add the alias as a second alternate email address. WHen I try that, I get an error saying that the alternate address cannot be the same as a profile name. Huh?

What is that error all about and can you use one of your alias's as a game center contact email?