I am using a navigation controller, and I have the style set to :
navController.navigationBar.barStyle = UIBarStyleBlackTranslucent;
But wh
I believe the UINavigationController assumes that your controller view frames don't include the area beneath the navigation bar.
UIBarStyleBlackTranslucent is more often used for UIToolbar, so Apple probably didn't make it easy to use it nicely with UINavigationBar. You'll probably need to abandon the UINavigationController, or start hacking the frames (careful with rotations), if you want to reliably render under the bar area.
Also, if your intention is to hide the navigation bar after a few seconds, you'll have a much easier time if you make it fade out (like the Photos app) instead of trying to slide it up (like Mobile Safari). Trust me on that one... that took me a lot of time to learn the hard way.