Use of the compass on Unity

Hi, I read the severals topics about compass, (http://forum.unity3d.com/threads/98828-sharing-gyroscope-controlled-camera-on-iPhone-4/page2 for example). But my question is this one : Does someone got good result with the compass trueHeading ? (Because the magnétic one is definetly not reliable) I want to associate it to my camera for the initialisation (to face north in my virtual world when I face north in reality). After the initialisation, the gyro will do the job. I still can't manage to make it work. Thanks