When I load a GPX, TCX, or FIT course (e.g. from RideWithGPS) into Garmin>NewFiles and eject the USB connection (I am using a Mac), the display flashes, the unit restarts, but no course appears in Saved Courses. Sometimes unexpected (perhaps working files) appear in Garmin>NewFiles or Garmin>Courses. But on the next try, they seem to get cleaned up. The process of importing courses to the unit seems to work correctly about 1 out of every 5 or 6 tries. Any suggestions how to get this to work reliably?