iphone - Back button don't appear in navigationController

Question

I have a UIViewController, with a navigationController, and I hide the back button. This viewController push a other UIViewController, and in the viewDidLoad of this new viewController, I do:

self.navigationItem.hidesBackButton = FALSE;

But the backbutton doesn't happear. Why? And this don't work when I pass to the new Xcode version for iOS 4.2, because in the latest version, it all works well.

Answer 1

Is there a title for the previous navigationController (on the navigation bar)? Sometimes, if there is no title, the first back button is hidden automatically.