You might try updating your Garmin. I haven't done it yet, but there have been 3 updates since I got it in early 2010. It took Jon the better part of an evening to get his to take, so be prepared to spend some time working on it.
I know what you mean about running volume, having started over at zero a bunch of times, now. It'll come back. You just need the patience to build slowly and steadily and not go out and overdo it.