Poking around a little more, I think it might be specific to querying by keyword...

Every time (over the past few days), I've gotten the same error message.  
Anybody know what coult be going wrong?  I am behind a firewall...

The error message:

403 Directory is not available

The directory in which the file /cgi-bin/bugs/css/buglist.css is located is currently not available for retrieval. Perhaps you can try later.

Get out of here!