Problems with iOS6 TurnBaseMatch

I came across some strange things when implementing a turn-based game with iOS6.

I created a bunch of matches and the game icon says “29”. But at startup:

[GKTurnBasedMatch loadMatchesWithCompletionHandler:^(NSArray *matches, NSError *error) {
}];

I get null matches back, and if I try to create a new one, I will get this error:

Error Domain=GKErrorDomain Code=21

What points to a new GKErrorTurnBasedTooManySessions

But I can not find these "sessions" and finish them!