I'm having exactly the same problem,too.
Hello all,
I'm having exactly the same problem with my Game Center on my iPhone 4S.
I restored ios several times a few month ago, but this problem didn't happen at that time. This issue is the first time for me.
Also, I already submit Apple's support community about this isssue, but no one replys for now:
https://discussions.apple.com/message/18600083#18600083
Just in case, the following is what I did/saw :
1. I already upgraded ios 5.1.1 and there's no problem about Game Center before restoreing ios.
2. I restored ios(iphone 4s) via iTunes ( ver. 10.6.1.7) on windows pc
3. After finishing the restore (I tried it with both backup and as-new-setup), launch Game Center app and log-in as my Game Center ID
4. Open "Friends" tab and see the friend list on the left of the screen
5. See description below all friends' name shows "Never Played"
I tried log-out and re-login Game Center, but this wasn't fixed.
I feel very sad to see my Game Center ID looks broken.
But I'm also guessing this issue comes from Game Center's server side, because this worked fine before restoring ios.
I'm wondering all I can do is wait for this issue's fix for now...
But I hope Apple's recognize this issue and this will fix very soon.