Hi, some issues with my TiVo series 3 (two s-stream cable cards, OLED front screen). I have comcast service in the bay area. One of my cablecards (card 1) seems to have lost it's ability to pair, and receives no channels. When I try to watch a channel, it doesn't even bother showing the 'no signal found message' (paraphrased), just a black screen. Under cable card pairing, the CableCARD(tm), Host, and Data fields are all zeros. The TiVo still trys to record shows on this tuner. The other cablecard/tuner (card 2) is fine. The three fields I mentioned above are all populated, and I can watch all my channels with no issues. Initially I was thinking that somehow the cablecard went bad, but after more reading, I am a little concerned that the Host field is all zeros for the first card. This should come from the TiVo? Is it safe to swap cablecards to see if the host field gets populated? Hoping for some suggestions as to how to proceed. Thanks in advance for your help.