I set up a series 1 Tivo (lifetime sub) about 4 years ago (remember PVTUpgrade?) using a Motorola cable box controlled by the serial port. I decided to upgrade the hard disk for 2 reasons:
1. The old one might be about to fail.
2. The new one would be bigger (500g vs 200g).

To accomplish the upgrade I bought a new version (2008) of InstantCake with TW and the software worked flawlessly. However, when I installed the disk and completed the 4-8hr indexing, I found that the serial port no longer showed as an option on the Cable Box Setup page (Tivo setup on the TV screen - not bash or telnet).

I read somewhere that I might need to reboot the Tivo and cable box for the option to show in setup. But I've not been successful - and I don't want to go back to IR blaster.

So I tried an experiment and put my old drive back in the Tivo. Then I went to the Cable Box setup and - The option of IR blaster or serial port showed up just fine. Also the serial port worked properly.

I've found very little on this problem from google etc. I just don't get it. If the cable works with the older InstantCake - why would it not show on the new one?

ideas?....