I did a bunch more testing, and I think I understand how to get it to work for me. But others of you might not like the scenario.
If you view the map while tracking, there are two data fields in the upper part of the screen. Touch either one, and you can select what data you want to be shown. Two of interest are the OFF COURSE, which seems to give the distance back to the course, and the TO COURSE, which gives a direction back to the course. (Rather than the TO COURSE, I prefer the pointer.) Since the accuracy of the unit varies from time to time, these data fields are just generalities, not precise guiding parameters.
What I've been doing if I want to retrace my track is to set a bunch of waypoints along the way. Then I save the track, make a reverse copy of it, and use WHERE TO to back-track along that copy. It correctly starts at the beginning and points me to the next waypoint. So the two data fields I use on the map are DISTANCE TO NEXT and POINTER.
TracBack also works in a similar manner if I set a bunch of waypoints going in. But if I use Tracback and later look at the data in Google Earth, it doesn't show the trip data (such as total track distance) separately for the inbound and return trips. By using the reverse copy rather than TracBack, I can look at what really happened in both directions
I was wrong in my earlier post about the unit ignoring the first waypoint; I was using it incorrectly.
Hope this helps.
geo