This has actually been a problem for some time (many TF versions, well over a year). Might just be my setup, but I can only download one track at a time to the Geko. When I try downloading a second one, nothing happens. No blue bar progressing. Thankfully all I have to do is cancel the GPS Transfer box and reopen it for the next track. Oddly, this doesn't happen while downloading waypoints. The GPS Transfer track download worked fine for this setup from the beginning (XP, serial, Gecko 201) and broke at some time in the past. I'm sorry I can't remember what TF version that was, but I think it was more than 2 years ago.
No rush (but annoying when headed out on week long trips).
Steve