Here's something weird I ran into the other day that may help somebody.. My buddy bought a 64st and brought it over for me to load up with tracks/waypoints. Didn't do anything different than I just did with mine - transferred everything with Mapsource - got the normal 'transfer complete' message. 90% of the content never showed up in the gps though. Garmin had no explanation/solution other than to use Basecamp. After screwing w/ it for an hour, it occurred to me to just copy/paste the .gpx files of tracks/waypoints from my computer to the GPX folder on the gps. It worked perfectly. Maybe I'm the only one who didn't know you could do that.. This is what the 64st GPX folder looks like when Mapsource transfers the files. My buddy's had my orig file names instead.