Ok - performed a master reset and that seems to have done the trick, but of course I have to reset all the specifications on my Garmin and I lost my last workout which did not sync. Happy that it seems to be working now (until the next glitch!) - but Garmin Express is certainly very buggy (this is the 3rd or 4th issue I have had with it - have had problems once every 2 months or so syncing data). I wish there was also a secondary way to upload data from my device to my computer as a backup. Oh well. Thanks to those who offered advice here. Until next time......