I broke my MythTV (Tivo thingy/dingy) a while back and finally put it back together last night. I even hooked up a client. I can watch TV on one box, and watch recordings on another. It is so sweet! Even though there is Jack-Squat on T.V. At least I can record all the Simpsons and watch them at my leisure.
My advice to anyone building a similar system (for troubleshooting): Power off and unplug, then plug back in, and boot up. That seemed to fix most my problems.