We have a Start 25 which usually performs ok. On a recent trip we noticed that the speed seemed to be "sticking". So it was showing a speed of, say, 35kmh and even when we had accelerated to at least double that speed it was still showing 35. After a while it seemed to come right but this happened intermittently for quite a while. I've connected it tonight to see if there's an update for it but there are only maps to download, no software update. When it was behaving oddly we wondered if there were insufficient satellites or something - on the device it was flicking between 9 and 10 satellites so that seemed to be ok. Any ideas?