After I upgraded to the new OS the button that locks the gyro orientation now clicks mute on and off and the lock button no longer stops the automatic rotation. Have you experienced this?
After the latest iOS4.x for the iPhone and iPad the ability to lock your screen seems to be missing. However, it is just hidden. Note that the steps below work both on the iPhone and the iPad.
- From any screen double-tap the home screen to reveal the active programs.
- Swipe the active program icon row to the right (to reveal a hidden area to the left)
- Tap the first icon. This is your rotation lock icon. As a bonus, you cal also control your iTunes from here as well!