My retrofitted NTG2.5 seems to have an intermittent issue. On occasion, it will show my position as being parallel to the road I am actually driving on - e.g. around 100 yards to the left on the road, in the middle of a field. As I move, my position is still updated correctly on the other axis, i.e. it is showing the current position as progressing alongside the main road in the correct direction of travel, so when that happens I can still navigate using the map display, but the navigation program obviously does not work because it keeps thinking I am off-road and all it does is simply trying to get me back onto the nearest road (e.g. 'turn sharp right' or 'proceed to the nearest road') rather than offer the way forward as it should. This used to happen on my old TomTom, but only when driving in the city on narrow streets between tall buildings, presumably because there was direct no-line-of-sight with some of the satellites. But with COMAND this happens when I drive out of town, for example on the A30 going east toward the M25. It will stay like that for anything from 10 minutes to half an hour, and them COMAND will miraculously find itself again and will work correctly from that point on. I tried switching off and back on both COMAND and the car, but this does not seem to help. It first happened some 6 months ago, but seems to have become more frequent recently. I am fairly certain the issue is with the unit in my car, not with the satellites, because when this happens I can still use my Nokia phone SatNav or the iPad, and both work flawlessly when COMAND looses its bearings. Could it be an issue with the GPS antenna, or perhaps it's a 'known issue' and there is some sort of software/firmware upgrade to resolve this?