[Brian]

I assume you've already done this, but open up Sync preferences on one of your macs and check the "Show Sync Clients" button. Are there duplicate entries or stale entries in the list? If so, you want to remove dupes and/or have the other machines sync to catch up.

If all dupes are removed and your devices are all caught up, you should see your database shrink after the first sync that's an hour later. (There are technical reasons that I can never remember when I'm writing one of these posts why we need to leave the files there for an hour.)

Turning sync off on a device doesn't do anything on the sync server. We leave all the files in place. You want to open up the Sync prefs and unregister it instead.

You may want to contact the support ninjas and let them lend a hand.