Autoration does not turn back on

In unity 3.5 when I show gamecenter using the prime31 plugin, the unity screen in the background flips upside down. I try turning autorotation off using this code: Screen.autorotateToLandscapeLeft = false; Screen.autorotateToLandscapeRight = false;

This does turn off the rotation, but autorotation does not ever work again even after I set these bools to true. Please help.