title: UIDeviceOrientationDidChangeNotification event not firing when user disable screen auto-rotation
body: <p>I can receive <code>UIDeviceOrientationDidChangeNotification</code> event, if auto-rotation is set.</p>
  
  <p>But when screen auto rotation is disable, orientation notification doesn't work any more.</p>
  
  <p>The effect I want to achieve is as iPhone Camera and Camera+: whatever the user lock or not lock the screen rotation, application can correspond to the rotation change immediately and correctly.</p>
  
  <p>Does anyone has any idea why notification not sent when user lock the screen rotation?
  How could I correspond to the device orientation change even if auto-rotation is disabled?</p>