Could not connect to Game Center server

Hello,

today I get this error message when I try to connect to Game Center (that until yesterday always worked).

I've tried changing password, connecting in the Simulator instead of my real iPod Touch 2nd gen, but nothing changed. I always get this message. And if I click on Create New Account, it says "Game Center account services are currently unavailable. Please try again later.". What can I do?

Is it a server side problem or I have to reset my iPod Touch, loosing all game saves (once again :-\ )?

I'm running iOS 4, and the iPod is NOT jailbroken.

Thank you for your help.