Orientation, two ViewControllers and NavigationController

Hi
I've got app with UINavigationController. It switches between two ViewControllers. Second of them supports landscape orientation and makes use of it.
Here is a problem: after rotating device into landscape position and getting back from second to first ViewController, this first ViewController is displayed rotated. As if it was allowing autorotatoin. But it even does not have shouldAutorotateToInterfaceOrientation selector! So I've got all UI elements misplaced after those munipulations. How can I prevent it?