I was using it yesterday and decided to use the autopilot since I hadnt used it in a while, so I pointed my boat in the direction I wanted to go and push the little button with the arrow and N on it and it started out in the direction it was suppose to, the all of a sudden it started turnin what looked like was to the north which was completely opposite of where I had it pointed I tried it a few more times and it would start out right and the after awhile it would start turning to the let as it was trying to turn to the north. anybody had this to happen to them ??