I've emailed the sysadmins to get them on this. As you have surmised, the machine is down and this is on the sysadmin side of things. Usually they are good about getting things back up quickly, but there may be some other issue here (and it is the weekend as previously mentioned).
This is pretty isolated, so it appears to have only affected GPU3, not GPU2. Since we've just introduced GPU3, there are fewer servers, so less redundancy. As we switch over, all servers will be GPU3 and there will be the full redundancy, which would also help in these situations in the future.
Prof. Vijay Pande, PhD
Departments of Chemistry, Structural Biology, and Computer Science
Director, Folding@home Distributed Computing Project