I went out on a day ride yesterday. I had created and loaded a ride plan track, but forgot to Show on Map until a few miles into the ride. When I went to look for it, that one and nearly all my tracks were gone. I managed to find a similar one in my Archives. When I got home I checked in Basecamp and it said all the tracks were there. But they were still gone when I disconnected the Montana from the computer. So I did a Master Reset and they came back! I did have a problem when I tried to eject the SD card earlier. But I keep all my tracks in Internal Storage. Another use for Master Reset.