I just imported some routes, about 500km each, from Mapsource into my Zumo. But I noticed that each route gained about 20 to 40km versus Mapsource! For example, a route that shows up as 480km in Mapsource becomes 500km in the Zumo. Any guesses why? I have no "avoidances" set in my Zumo or in Mapsource, and the routes look like the same shape on the Zumo screen as in Mapsource, so it's not like the Zumo is routing me differently (as far as I can tell). I never noticed this problem before, but then I never really checked for it either. My best guess is that maybe the Zumo is sending me back and forth along a route, making me retrace my steps. This would be essentially impossible to see just by looking at the shape of the route on the Zumo screen. Zumo masters, what's going on?