That fits our scenario as well. Everything was fine on both of our Tivo HDs, then the firmware was updated on the card for one of our boxes around October and that box started having the disappearing channels problem. Our other Tivo HD never had a problem until about a month ago when we had a power outage and the firmware was updated on the cablecard when it booted back up. Now it does the magic disappearing channel trick as well. I should have written down the firmware version on it when it was working properly. With all of the problems, it seems strange that SA can't just "roll back" the firmware update that seems to be the source of the issue.