said by Heinrich:Well I didn't specify but this was simultaneous recordings of 24 in HD on the HD local Fox channel and also HEROES on HD on the local NBC HD channel.
(and, no OTA antenna)
The point tishoo was making was that both of these programs are on local HD channels, most likely, not encrypted. This means that you could receive them even without cable cards as long as your TV has a QAM tuner. All these cards are doing for those channel right now is making your Tivo match the channels HD feed (something like 90.1, 102.3, etc) to the channel it is shown on in the cable system (502, 806, etc).
Since your Tivo has had the card installed and now recognizes the corresponding channels for the local HDs, it is able to easily record off of both channels at once without any need for the cable card.
As for your encrypted channels, however, you will still need the cable card to receive these, in case you were to think you could ditch the card and still receive them without.