Yesterday everything was fine. Today Mapsource won't show anything less than an interstate on the map. No matter how much I zoom in or how high the map detail is it will only display primary roads. WTF!!!!! I'm pulling my hair out here. Of course I don't have the disc here to try and reload it but can anyone think of why it would be doing this in the first place? Just when I thought I had the thing pretty well mastered....
While it seems your problem was with the detail level, another cause for loss of secondary road display is accidentally using the "Trip and Waypoint Manager" as your source, rather than the "City Navigator North America" (selected in the upper left drop-down box).
The most frustrating element of MapSource for me is the lack of coordination between routes you design in MapSource, and those that result in the device (I use a eTrex Vista Cx). Unless you intentionally indicate many points in MapSource, the device will very often design a completely different choice of roads when you have it calculate the route, In other words, if you select a destination in MapSource and have it generate a route, and then transfer it to the device, the route you end up with is almost always different. You can get around this problem by selecting a boatload of intermediate waypoints, but you shouldn't have to! Even with a zillion waypoints, the device might make different choices to get between them. The only reason to use MapSource is to see your actual route, so I don't get it. A software feature allowing the user to transfer a route to a device should TRANSFER THE ROUTE, not just the destination(s) and/or waypoint(s), otherwise, why bother with MapSource?
This is due I believe to differences between the MapSource "Routing Preferences" and the preferences in the device; they are not all the same, and therefore they do not transfer the specific routes generated by the device (perhaps this is device-dependant). It's like MapSource was designed by a separate company that only glanced at the hardware it was supposed to interface with.
Comments about the need for tutorials are right on. I've been using my Garmin device for quite a while and I still don't know what some of the "features" do, because there is no mention of them in the pathetic manual.
Sorry for the rant, but while I believe Garmin makes great hardware, their software, documentation, and support are horrible IMO.