App crashes on iPhone 4?

Question

This code causes my app to crash on an iPhone 4 and on the simulator but works perfectly fine on a 3GS. Any ideas why this might be?

-(IBAction)startButtonClicked{

 GameViewController *screen = [[GameViewController alloc] initWithNibName:nil bundle:nil];
 screen.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
 [self presentModalViewController:screen animated:YES];
 [screen release]; 
}

Answer 1

Have you checked out what's happening in screen's viewWillAppear and viewWillLoad methods? It looks like some issue in your init code there. Where are you opening a URL?