iOS 6 UI interface Orientation - shouldAutorotateToInterfaceOrientation: Not working

UIInterfaceOrientationMask.h

typedef enum {
    UIInterfaceOrientationMaskPortrait = (1 << UIInterfaceOrientationPortrait),
    UIInterfaceOrientationMaskLandscapeLeft = (1 << UIInterfaceOrientationLandscapeLeft),
    UIInterfaceOrientationMaskLandscapeRight = (1 << UIInterfaceOrientationLandscapeRight),
    UIInterfaceOrientationMaskPortraitUpsideDown = (1 << UIInterfaceOrientationPortraitUpsideDown),
    UIInterfaceOrientationMaskLandscape =
        (UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight),
    UIInterfaceOrientationMaskAll =
        (UIInterfaceOrientationMaskPortrait | UIInterfaceOrientationMaskLandscapeLeft |
    UIInterfaceOrientationMaskLandscapeRight | UIInterfaceOrientationMaskPortraitUpsideDown),
    UIInterfaceOrientationMaskAllButUpsideDown =
        (UIInterfaceOrientationMaskPortrait | UIInterfaceOrientationMaskLandscapeLeft |
    UIInterfaceOrientationMaskLandscapeRight),
} UIInterfaceOrientationMask;