So, naturally I replaced the hard disk. I could have gone with a "name brand" (Weaknees), but that would have cost about $250 for a 1TB disk (loaded with the Tivo software). Instead I went with eBay and got the same 1TB disk with Tivo software for $150. But the disk had a problem. The seller graciously sent me a new one before I even sent back the old one, and this had a similar problem - so I suspected it was my Tivo. Here's where it gets interesting.
- They never should have suggested I use a 3rd party to update the disk.
- They won't give me any help of any kind to get it to work.
- Since I opened the box, my non-warranty was invalidated, and they wouldn't even give me a trade-in box.
After speaking to 3 managers and higher level tech support, they maintained they would do nothing, nor give me any help of any kind. So in other words, my hard disk crashed (a pretty common occurrence for a hard-disk based system), and Tivo effectively said "toss your box in the garbage and buy a new one".
As it turns out, I did a "Clear and Delete" everything on the new disk, and it fixed up the flakiness, and I now have a perfectly functioning 1TB Tivo Series 3 - which I still love, but a bit less now that I know how little Tivo is willing to support their customers.
Tech details: The problem I had with both disks was an "error #51", "hardware malfunction". It turns out that this commonly happens when replacing disks because of a mismatch between device and drive ID used for encryption. "Clear and Delete" is the standard procedure to fix this. But for the first disk, it did something bad because the box would never boot again. Thus, I was very reluctant to try it a second time. But when I had no choice, I did - and magically, it worked perfectly. I don't know if there was something wrong with the original disk or if there was a software screwup of some kind.