So I've just purchased Angry Birds Space off of the store for £0.79.
I go to the game, start it up, wait a few seconds on its home screen and a message pops up saying 'Sorry, we can't sign you in. Please sign in at xbox.com, then start this app again'
Obviously I took this advice and did just that. Tried again, same problem. I'm already logged in on the phone itself, and other games notice my gamertag just fine.
Does anyone know a way around this, because I have only just recently purchases my nokia lumia 820 and already it is providing a number of problems.