[whpalmer4]

And just one more question, which probably isn't the case, but your description doesn't rule out:

you did do a sync on the iPod as well after the desktop Mac sync finished, right? The sync mechanism simply applies the changes to a central repository, and they aren't seen by the other device(s) until the device does a sync of its own.

With Bonjour sync, the desktop app has to be running when your iPod tries to sync -- that could explain the original case you described. You made the change to the repository, but before the iPod had a chance to do a sync and pick it up, OF was no longer running. The sync doesn't push data, in other words, it just makes it available for other devices to read when they finally do so either because you start up OF (and don't have auto-sync on open disabled) or a minute goes by after you make a change, or an hour since you last made a change, or you manually invoke the sync.