UINavigationBar occasional glitch

When I press back twice really quickly on the UINvaigationBar, then the UINavigationBar animates before the view, and then when the view finally animates the bar becomes blank. When I NSLog(@"",self.navigationItem.title) is prints the correct title. Does anyone have any ideas 开发者_StackOverflow社区how to resolve this?

I've seen this happen when the init/loadView of a view controller that's being pushed takes a non-negligible time- perhaps the viewWillAppear of your new view controller or the viewDidDisappear of the old is taking some time?