Sorry for the trouble here! One possibility here is that database being synced is very large - folks that have never synced before sometimes haven't ever needed to turn on the Archive database on their Macs, so there are large numbers of completed actions still stored in their database.
If you run through the steps in
this thread, do you see any change in the sync behavior?
If not, we'll be happy to help, but it's probably going to be easiest to do so via email; if you contact our
support ninjas, they'll be happy to help.