iOS 6 bug: supportedInterfaceOrientations not called when nav controller used as window root

Question

In my mainwindow.xib I have a navigationcontroller. On top of (as a sub item) I have another viewcontroller(homeviewcontroller).

In the nib I have set the window\

Answer 1

To elaborate on @phix23's answer, I wrote this tiny UINavigationController subclass

@implementation MyNavigationController

- (NSUInteger) supportedInterfaceOrientations
{
    return [[self topViewController] supportedInterfaceOrientations];
}

@end

From my understanding of the docs mentioned in his comment, this should be the default behavior. But somehow this works for me, while without it, it doesn't