ST6001 Calibration

I cant seem to calibrate my ST6001 Autopilot. I follow the manual instructions and it keeps directing me to keep doing circles, i did about 20 circles tonight before giving up. I did many 2 minute circles at less than two knots but it wont move on to the next stage.

The compass heading on the autopilot doesn't match the boat compass so the autopilot keeps sending me off on a crazy direction every now and then. The autopilot is hooked up to a Raymarine C120.

Any help would be appreciated.