I have a Garmin GPS 60csx. I have download several tracks already to .gpx and uploaded them to Garmin Connect with no problems. I do have an issues exporting the .gpx from Mapsource(which appears to be a known issue but only for a few people...) so I use Bascamp.
I get the following error when I try to upload a single track that displays ok in Basecamp, Google Earth and GPSMapEdit.
"Some activities could not be created." With no activity uploaded.
I have tried several times with the track and it fails. I have inspected it point by point in Mapsource and it seems to be ok.
I am attaching the .gpx file in case anyone wants to check it for me.