I'm having problems uploading activities from my Garmin 310 xt this week. I can find the tcx files in my history folder, but Garmin Connect is not pulling them in. If I try to manual upload all new activities, it doesn't find them. If I manual select and try to upload the tcx files, I get an error: "An error occurred with your upload. Please try again." I hope this is just temporary!
PS: I also tried manually uploading an older file that I know was already successfully uploaded in the past. It gives same error.