The hard drive on my Tivo was making some bad sounds. Finally I saw this:

Ouch! I have one of the first generation Tivos, so it's almost 5 years old. It's not too suprising that the hard drive would die after all that time. I was able to easily order a new drive A from http://weaknees.com, and get things running again within a couple of days. I ended up losing everything on it though...

I really should have gotten a second Comcast DVR instead. I was so anxious to get my Tivo working again, I didn't give it enough thought. It has two tuners, it supports HDTV, and it would take quite a while for the monthly fee for a second box to catch up to the cost of the new hard drive.