My simrad autopilot with RC42 rate compass is connected to my E120 RM. Returning from the Bahamas my autopilot compass was not aligned with my mag compass and was off approximately 90 degrees. Sometimes it would let me set auto on the pilot with the heading off 90 degrees and it would hold the course I was headed. Other times the ap compass starting turning and it would not hold a course. The heading shown on the RM is the same heading that is shown on the AP control. The ship on the plotter is turned 90 degrees even if you are heading in the correct direction and on a straight line. Any ideas is this a rate compass issue? Can it be rebooted?