This is purely for the benefit of people who may be googling for this piece of information, as I have been for the last 2 hours with great frustration. You’d think uploading a GPX file to the unit is simple and is just a matter of mounting the unit’s SD card and copy your file where the others GPX files are. Wrong. Grrr.
Here’s how I did it: download LoadMyTracks, plug your unit, but do *not* mount the card, then press “Send…” and select your GPX file.
[tags]gpx, gps, garmin, max, osx[/tags]