ios 7 auto resize UINavigationController when In-Call status bar is toggle Monotouch

Question

I'm having a problem when the in-call status bar it shows, I have tried.

navigationController = new UINavigationController ();
        navigationController.NavigationBarHidden = true;
        navigationController.View.AutosizesSubviews = true;
        navigationController.View.AutoresizingMask = UIViewAutoresizing.FlexibleHeight|UIViewAutoresizing.FlexibleMargins|
                                UIViewAutoresizing.FlexibleTopMargin|UIViewAutoresizing.FlexibleBottomMargin;
        navigationController.View.SizeToFit ();

window.RootViewController = navigationController;
        window.RootViewController.View.AutosizesSubviews = true;
        navigationController.View.AutoresizingMask = UIViewAutoresizing.FlexibleHeight|UIViewAutoresizing.FlexibleMargins|
                                                     UIViewAutoresizing.FlexibleTopMargin|UIViewAutoresizing.FlexibleBottomMargin;

but is still pushing bottom all views, hiding all buttons or controls at the bottom of the view, I also tried the same code in the Root View controller and doesn't work.

I'm using flexible UI for all controls this way:

btnContacts = IOTM.GUI.CreateButton ("MainMenu/btncontacts.png", 0f,Frame.Height  - (Frame.Height * 0.225f), Frame.Width, (Frame.Height * 0.075f));

and I'm also hiding Navigation Bar

Can someone help me? There is another way to auto resize view or detect changes in status bar to reload my views?