Firstly, HAPPY BIRTHDAY drake57!
Secondly, I had a real "Oh shit, I waited around for nothing" moment today while the cable guy was diagnosing things. It wasn't the cable modem that went bad. It wasn't the node to the house that went bad. And actually, I already *knew* the first part of the problem and thus how to diagnose the solution, but my brain didn't put two & two together until the cable guy was working.
I have a D-Link wireless router to create a nice home network. And I noticed on Sunday night that the router's password had reset to the default. I should have then realized that if it completely reset itself, it also reset it's speed back to 100Mb/s. A speed that my cable modem, apparently, can't handle. So all I needed to do then (theoretically) was change 100 Mb/s to 10Mb/s. And I wouldn't have had to wait until Wednesday.
Alas, the problem isn't as simple as that. Even after changing the speed on the router, I still wasn't getting an address from RoadRunner. I just didn't have the time to work on it then (and decided to wait until I get back from Boston on Monday) so I have the PC hooked directly to the modem for now. And everything's just peachy! (The cable guy also got to feel like he did a good job getting me back online, even though he really didn't do anything to get me connected again. Still, his futzing about is what caused me to do the correct math and solve the problem.)
It took me quite awhile to get caught up in e-mail and now it's time to do likewise with reading my LJ friends list. Joy joy! :-)