LoadMyTracks works fine sending a single file to my device, but each time I send a GPX file, it deletes the information from the previously sent file. How do I send information from more than one GPX file?
Garmin GPS devices in particular tend to delete track and/or lap data when you download to them (although this isn't necessarily true for all Garmin devices or all types of data). When using these devices, you must send all of the data at the same time, or risk having the data overwritten by the next Send command.
Fortunately, LoadMyTracks allows you to select more than one GPX file to send at a time, by shift-clicking on multiple files in the file panel for the Send command. To do this, all files to be sent simultaneously must be in the same folder.