Today I pulled up my map and saw immediately that it was lost. The arrow showing direction of travel is still oriented correctly, but the location is off by 1/4 to 1/2 mile. I restarted the car and even tried to reset the nav function but it is still wrong. HAs anyone experienced this? Its worked perfectly up to this point. I have version 4.63 on my PCM 3.1 unit, btw.