Assuming that you're adding your navigation bar at 0,0 then it looks like you're view isn't positioning correctly.
The easy fix is to move your bar to be at 0,-20
UINavigationController *naviController = [[UINavigationController alloc]init];
CGRect frame = [naviController frame];
frame.origin.y = -20;
[naviController setFrame:frame];
[self.view addSubview:naviController.view];
However, that's a hack.
Try something like this instead :
[[self view] setAutoresizesSubviews:YES];
UINavigationController *naviController = [[UINavigationController alloc]init];
[naviController setAutoresizingMask:UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleBottomMargin];
[self.view addSubview:naviController.view];
That might work?