Problem: If user is not logged into GameCenter account - GameCenter authentication view is launched in portrait mode (in ios 5 there were a modal dialog) asking to log in. B
I have found that the problem is coming from the Game Center in my case. When in the simulator I do not have the Game Center initialized yet, it would like to pop up the login view, but in portrait mode. Once it is reaching this point it crashes if I disallowed portrait orientation. Strange bug in the OS as Game Center should take the allowed orientations only to be inline with our intention of landscape user interface.
I do not have the solution yet, but I will post if I find it.