Game Center issue in iOS 6 - ios5

Question

I am implementing Game Center in my app and I am having an issue trying to read the leaderboardCategory property in iOS 6.
Here's how I'm presenting the GKGameCenterViewController:
GKGameCenterViewController *gcViewController = [[GKGameCenterViewController alloc]init];
[gcViewController setLeaderboardCategory:currentLeaderboard];
[gcViewController setGameCenterDelegate:self];
[self presentViewController:gcViewController animated:YES completion:NULL];
[gcViewController release];
Then when the delegate is called, I check to see what the leaderboardCategory property shows:
-(void)gameCenterViewControllerDidFinish:(GKGameCenterViewController *)gameCenterViewController{
NSLog(#"%#", gameCenterViewController.leaderboardCategory);
}
The trouble is that no matter which leader boards I switch to before dismissing, it always shows the first one I passed in.
According to Apple's docs:
When the leaderboard is presented, the value of this property
determines which leaderboard content is displayed to the player. As
the player changes which leaderboard content they view, the
leaderboardCategory property is automatically updated. For example, to
preserve the player’s selections, you can read the leaderboardCategory
property after the screen is dismissed, and set that value the next
time you initialize the view controller.
Now, I tried using GKLeaderboardViewController as well, but with no success. However, when I use GKLeaderboardViewController in iOS 5 (GKGameCenterViewController isn't available before iOS 6), the "category" property is updated as Apple's docs suggest.
What am I missing?