I was dealing with this during the imusic launch and furiously troubleshooting cursing Apple as they were no help BUT I digress, you may want to stry logging into the actual itunes APP from your laptop. I never open mine anymore, hence imusic!
I tried two things that lead me to MY solution and it may be yours as well.
When logged into your itunes account app on your laptop access your "account info" by clicking on the drop down menu on the right upper hand of the window.
Update your account info if needed otherwise just verify your security code info and click done. In my case this prompted a red window that told me this computer needed to be authorized and that in order to complete my appletv purchases, I would need to complete the following steps:
Access the "authorize this computer" option from the store menu on the top left area of the window.
I discovered all of my stolen/damaged laptops totaled 5!! This one was not authorized as it was a gift from my partner.
So I deauthorized all computers. Whether you need to do this varies. I would consider what other apple devices you have before taking this route.
Now I finally go back to my apple tv yet again and......SUCCESS!
Mind you this all started with the CREDIT CARD DECLINED message which is where my journey began so this should also be a troubleshooting item for that as well. Please pass on and oh yeah, I don't get the watch!!!
I hope this helps some of you! Happy Independence Day!
