How come when I download tracks & waypoints to my GPSr they due not overwrite the previous version....they instead duplicate the track or waypoint out on the GPSr. For example if I have a track named 'abcd' on my GPSr and then edit and re-download I'll now have 2 "abcd" tracks on my GPSr.
What model GPS do you have and what software are you using? You need to be a little more specific...
I have a Garmin 400T with mapsource.