From their web site news
Technical News 22 Apr 2010 4:28:46 UTC
We had a couple of problems tonight. ptolemy, our main file server for user accounts went down at about 5:05pm. Of course that's 5 minutes after Matt and Jeff left, so that left me as the default sysadmin. They're both more patient than I am and are less likely to just pull the plug out of the wall. So I rebooted ptolemy, and it crashed again about 5 seconds after it came back up. And again. And again. Eventually I figured out that vader was trying to do a lot of writes to ptolemy and that was causing the crash. I couldn't get vader to respond to anything, so I just pulled the plug out of the wall. I tried a few times to restart it, but it just hangs during the boot process. So our assimilators are down, among other things. We may run out of work at some point. Hopefully Matt or Jeff will fix it tomorrow.
EDIT: The server status page says that all is running and there are work units available so I guess it is fixed.