I have an MKII.

I just updated my software to the most current version relevant to my unit. Worked fine.

My PDOP is <5. I have several satellites with S/N higher than 10. I am receiving 8 satellites.

Dead-reckoning signalling is working properly. Gyro is workin properly.

I compared my location coordinates with my friend's portable GPS and the system has me in the correct spot.

BUT..............

The triangle indicating my position does not move at all when I drive. It spins, but it does not move forward.

I am not placed properly on the map. Sometimes I am 5 miles away...sometimes elsewhere, although I am always in my city. I have owned the car since fall. It has had plenty of driving time to "find itself." Actually, I do have proof that the GPS knows my correct coordinates, so I can't explain this at all.

I can manually place myself on the map using the system's function for that. However, I am then "stuck" wherever I placed my position. I don't move; only rotate.

OCCASIONALLY (maybe every several weeks t best) the map randomly updates to my current, correct location. However, at no point does the triangle move with my car. It always stays static.

HELP!!!!!!!!!!!!!!!!