After much cussin' and testing and talking with Comcast reps last night, we have a service call in for tomorrow morning. Somewhere between the modem and the provider, that cable is going bad.
I hope they can pinpoint the place where the trouble is and get it fixed fast. I wanna be online!
At this point I'm tempted to wax philosophical about my relatively recent dependency on the internet. As it is -- I gotta get back to work. See you all Friday, I hope! (why yes I will be back to my usual lurking, eh heh)