I have been using an Airmap 2000C GPS in my -6 for two years. There has been several times when I had an airport selected, I could clearly see the airport and the GPS was pointing 10 or 20 degrees off. This weekend I was returning from the Bahamas to West Palm Beach. I was lined up on the localizer but my the GPS was pointing 20 degrees to the north. I re-entered the airport several times with the same result. I notice too that whenever I set a radial to a VOR there is a slight to significant difference from the OBS in my panel. I have updated the software twice. No joy! Has anyone else experienced this?