Game Center leaderboards won't show up

Okay, I've been trying to display the Game Center leaderboards in my Cocos2d iPhone game. I have progressed and I got this piece of code:

- (void) showLeaderboard {
tempVC=[[UIViewController alloc] init];

GKLeaderboardViewController *leaderboardController = [[GKLeaderboardViewController alloc] init];
if (leaderboardController != nil)
{
    leaderboardController.leaderboardDelegate = self;
    [[[CCDirector sharedDirector] openGLView] addSubview:tempVC.view];
    [tempVC presentModalViewController:leaderboardController animated: YES];
}

}

When I run that in the simulator, I see it becomes portrait mode, so I know something happened. BUT nothing appears. No leaderboards come out. What is wrong?

• My application is already linked with the iTunes thingy.
• I am authenticated at the beginning of the game sucessfully.
• I already submitted scores (with a nice thing called GameKitHelper)
开发者_StackOverflow

Go to the AppDelegate.m and change:

[window addSubview: viewController.view];
to
window.rootViewController = viewController;

then call it

GameKitHelper* gkHelper = [GameKitHelper sharedGameKitHelper];
[gkHelper showLeaderboard];

This works on cocos2d 1.0.0 RC1