Hi, Beej,
We'll usually respond on the forum if we're able to reproduce your issue in-house, but unfortunately we haven't been able to. In order to solve your issue we need to find something that will help us track down the cause; could you answer a couple questions that might help me get started:
1. Has it ever gotten "stuck", so that it stayed out of sync no matter how many times you switched between the Fusion and another Mac application? (up to the point before you re-try the copy)
2. Has it ever failed when you're running only a few Mac applications?
I realize that asking you to diagnose the issue is disruptive to your work, but if you could note whether it is more likely to happen under specific conditions, e.g. running X11, or with a particular XP application, etc, it may help in diagnosing the problem.
Also, please attach the vmusr.beej.log file from August 13 if you still have it, or enable logging and attach it the next time the problem occurs.
Thanks,
/Steve