Keep in mind, there are many players involved.
There are many times, and I will stress many, that an outage will happen during the maintenance window, that the ISP, or Covad is unaware of, because it is at the carriers level, and if they don't inform Covad, Covad can't inform the ISP.
In Doctor Olds case, he had sync, but no IP, so, without any more info then that, I know he had a good connection to the DSLAM (he had sync), but no IP, which means, 1 of 2 things, either there was a outage between the DSLAM (Transport circuit), and the ISP's Radius server, or the ISP's Radius server, and Covad's RADIUS server.
It could have been a server, or more then likely, a transport circuit down in between (DS3, fiber, etc).
And in some cases there is emergency maintenance that the carriers do, and don't have time to notify Covad and others.
So in short, if you are down from 1am - 5am local time, just assume it is maintenance, and if not back up by 5am, call in for support.
EDIT: One additional point that I would stress, it isn't Covad's job to support end users, except for covad.net users. So they have no reason to post a public maintenance page for other ISP's users. This is what the ISP's do, or don't do. I will state as a partnered ISP, we have access to see all current, and scheduled maintenance for the entire network. So unless Covad wasn't notified, all partnered ISP's can see what Covad is or isn't doing, as far as outages, and maintenance.--
Lightning Bolt Technologies