In the MainViewController I have to adjust some images on orientation change. Easy - just add the code to the willAnimateRotationToInterfaceOrientation: callback
Isn’t this the correct behaviour? Because the animation callback should only be called before the animated orientation change. When you pop the topmost view, you see the pop animation and then the already rotated view underneath. There’s no rotation animation and therefore no callback. (But you should certainly receive willRotateToInterfaceOrientation:duration:.)
P.S. I have a sample Xcode project for interface orientation experiments on GitHub, you might be interested.