Zig Zagging Tracks With Mapsource Maps

[revrnd]

I have found in the past if I'm riding my MTB or snowmobile on a trail that is parallel to a road, that the track would zig zag from my actual position to the road & back. I had tried several suggestions (including turning off "Lock On Road"), but nothing worked. Then I tried loading a non-Mapsource snowmobile trail map into my Legend Cx. The next ride out I rode 1 of the problem areas & got a perfect track. The following trip I had TopoCanada installed, but selected "Hide TopoCanada". Again the track was straight & where I was riding.

 

So I guess there must be an issue w/ Mapsource that makes it think if you're riding near a road, you actually are on the road.