I have had my Garmin Vivofit for 8 months and used to sync it with my laptop once a week. Last week, I was on vacation and did not upload the data right away. I tried after 2 weeks and nothing uploads, although the Vivofit shows "sync". The on-line data stats still have the data from 2 weeks ago only. The Vivofit still counts steps, distance etc. but I can't get the data on the website anymore. I used Garmin Express and then logged on to Garmin Connect, but it does not show new data anymore. The Garmin software installed on the laptop is current. The laptop uses Windows 8.1 and the ANT USB-M key does not seem to work on the USB 3.0 port or the USB 2.0 port.
