IIRC "Lock on Roads" does not have to do with routes, rather it will move your position arrow to a road if you are close to a road. It assumes if you are that close to a road (due to position error) you must really be on the road.
Now, onto your original question. Did you check the "Include Route Calculation Data" on MapSource when you loaded the maps to your GPS? If not, it will be routing on the basemap. in that case, the route line follows the road on the basemap, and the City Nav map overlay will be on top of it. the basemap and the detailed maps don't always line up, and I believe would produce the results you are seeing.
I've been playing with it for a while, but still have no luck. I've looked all over for "Include Route Calc. Data". I have City Navigator v8 and what it shows when I select "Send to Device" is check boxes for "Maps", "Waypoints", "Routes", and "Tracks". I've looked in the "Help" files under several different categories, but with everything dealing with "routes".
Both the PC and gps are showing the information from City Navigator. On the gps, it is showing the turn-by-turn directions, but in the map view, the routes don't exactly fit the roads. For example, if there are some curves or zig-zags in the road, the gps is showing a straight line path from the beginning to the end of that road. Then, if there is a turn onto another road, the gps will show the turn.
Yet, if I have my gps calculate its own route to the destination, the routes do line-up with the lines of the map. If I transfer the route from my gps to my PC, it shows up fine. It just seems when I go from my PC to gps, it's having some problems.
What I've been trying to do is take the information from my AAA Trip-Tik and put it onto my gps. I spent some time plotting the route on my PC and figured it would be nice if my gps would follow the same route as the hard-copy of my trip-tik. Too bad AAA doesn't have a feature so that the trip-tik could be directly downloaded into a gps.
Does anyone have any suggestions? Any help would be greatly appreciated.
Thanks,
Dwight