I think I may be the one who originally posted this issue, so I just took the easy way out and rebooted when I left each day. However, I've been up for several days now and the issue has not reoccurred. My strictly personal opinion is that it WAS a Microsoft issue all along --- even though they never acknowledged it --- and that one of the updates finally fixed it.
But watch, now that I've said that, it's going to come back! :(