Originally Posted by Tourist in MSN

I do not know why this happens, but i have occasionally seen it over the years in some of my tracks. It only seems to happen when my GPS has not been used regularly for weeks.

I suspect that the GPS has old data in it for some of the satellite orbits, and as some satellites move further away and another satellite comes into view, if the data on the orbit is old for the one that just came into view, I suspect that it plots the location using old data with some error. This is only a guess on my part.

If my guess is correct, the best solution is have your GPS turned on more often to load more recent orbit data for all satellites into it.