My Tivo has been unable to make a daily call since the middle of September due to a lack of internet / phone line. The moment I tried a test call it got stuck in a fatal reboot loop!!
Here's the details: I moved house middle of September and only yesterday got an internet connection. I had been using my 1.0b Tivo without the network since I moved. After about 10 days the TV listings vanished as expected but I carried on using it to give me the "pause" tv if nothing else.
I got an internet connection last night and tried to make test call.. Navigated to phone/network connection, selected "make test call" and about 15 seconds later the tivo rebooted.. then rebooted.. then rebooted.. It wouldn't stay up for longer than 15 seconds after playing the intro video. I tried a few kick-start codes, and even managed at one point to get to "restart guided setup" but it seems to be very very unhappy..
I've seen this before, but it was always due to a dead disk.. In this case, the disk was fine. I removed it last night and installed 1.0c after giving the disk a bit of a burn in check.. The tivo is back and running happily now, with up to date program info.