I am getting the same error with my Garmin Etrex 20 on Mac 10.6.8 and Chrome simulating Mac Safari 4. I can't use Chrome because it can't even see the Etrex at all (though garmin.com says I'm hooked up with no problems). I know this worked on 12/28/11 because I was able to load geocaches on my Etrex then, but now I am getting this error (just logged on again yesterday). I don't think anything has changed on this end, so...