The gyroscopic tilt-meter does not appear to work correctly, how can I fix it?
Any issue affecting the Gyroscopic Tilt-meter is usually driven the iPhone settings you might have in use. The following steps will allow you to reset the Gyroscopic Tilt-meter and have it work as designed:
1. In the Settings, go to: Privacy > Location Services > System Services > Compass Calibration.
2. Make sure that the calibration setting is checked (active).