Stations 1, 7, 9, 11, 19 and 20 all lost contact with the domain controller; 19 was successfully removed and added back into the domain, but as of this writing, Greg is still working on the others. We have heard that Cisco routing equipment is reputed to be the cause of this kind of thing. Caused problems for a Russian class in the lab. Greg will probably add more detail later; he was out when it happened, so I caught the initial request for help and spent an hour on it.