I recently got a forerunner 610 watch and a vivofit. The watch says its syncing but just stays at the same time (7 minutes remaining..), on the bottom its says uploading to garmin connect (waiting to transfer). The vivofit doesnt do anything and says error uploading to garmin connect.
Were you previously using the ANT Agent to sync your 610? Have you tried completely uninstalling all Garmin software, deleting/renaming all folders on your computer named Garmin (there are a few, even after an uninstall), and then re-installing Garmin Express?