There are already a couple of questions on this but I followed their steps to solve it and it doesn't seem to work for me. Here's what I have done:
1. I double checked to have the bundle identifier in the xcode project to be the exact same as the provisioning profile found on the provisioning portal (it also says Game Center is enabled). No wildcards.
2. I have logged in using a sandboxed account to gamecenter (made 2 accounts incase one wasn't sandbox). I did see the word "sandbox" with some numbers/letters on the top left while signing up for an account, so I'm 100% sure I have a sandboxed account. Tried 2 different sandbox accounts. Tried on 2 different devices (ipad/iphone). Also tried on the iPhone simulator.
3. I have deleted my app from my iPhone many times and tried it again.
I'm running 4.3/xcode 4 on iPhone + iPad. I'm still receiving the message. Any help would be appreciated. Thanks!