UINavigationBar disappear after iPhone rotation

I have an app that sets the UINavigationController in the didFinishLaunchingWithOptions method like this:

 main_iPhone *mainiPhone = [[main_iPhone alloc] initWithNibName:@"main_iPhone" bundle:nil];
mainiPhone.navigationItem.title = @"TitleHere";

UIBarButtonItem *botaoSobre = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:mainiPhone action:@selector(goToAboutView)];
mainiPhone.navigationItem.rightBarButtonItem = botaoSobre;

navController = [[UINavigationController alloc] initWithRootViewController:mainiPhone];
navController.navigationBar.tintColor = [UIColor orangeColor];
navController.navigationBar.translucent = NO;

[self.window addSubview:navController.view];
[self.window makeKeyAndVisible];
return YES;

When I run the application, the navigation bar appears correctly only in portrait mode. However, when I rotate the device to landscape the NavigationBar disappears. When I rotate back to portrait way I also don`t get the NavigationBar back.

PS: My mainiPhone.xib file has 2 views (one in portrait mode and one in 开发者_开发问答landscape mode). I switch the views inside the mainiPhone.m like this:

- (void)willAnimateRotationToInterfaceOrientation:

(UIInterfaceOrientation) interfaceOrientation duration: (NSTimeInterval) duration {

if (interfaceOrientation == UIInterfaceOrientationPortrait) {
    self.view = self.portrait; 
    self.view.transform = CGAffineTransformIdentity;
    self.view.transform = CGAffineTransformMakeRotation(degreesToRadians(0)); 
    self.view.bounds = CGRectMake(0.0, 0.0, 320.0, 460.0);


} else if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft) {
    self.view = self.landscape; 
    self.view.transform = CGAffineTransformIdentity; 
    self.view.transform = CGAffineTransformMakeRotation(degreesToRadians(-90)); 
    self.view.bounds = CGRectMake(0.0, 0.0, 480.0, 300.0);


} else if (interfaceOrientation ==  UIInterfaceOrientationPortraitUpsideDown) { 
    self.view = self.portrait; 
    self.view.transform = CGAffineTransformIdentity; 
    self.view.transform = CGAffineTransformMakeRotation(degreesToRadians(180)); 
    self.view.bounds = CGRectMake(0.0, 0.0, 320.0, 460.0);


} else if (interfaceOrientation == UIInterfaceOrientationLandscapeRight) { 

    self.view = self.landscape; 
    self.view.transform = CGAffineTransformIdentity; 
    self.view.transform = CGAffineTransformMakeRotation(degreesToRadians(90)); 
    self.view.bounds = CGRectMake(0.0, 0.0, 480.0, 300.0);
}

}

Also, my shouldAutorotateToInterfaceOrientation method just returns YES.

What am I doing wrong? Thank you very much in advance!