My setup: San Francisco, CA: Comcast 2 Tivos in home: 1 Premiere & 1 Comcast Cable Box in room. 1 Tivo HD in other room About two weeks ago I found recordings on a few HD channels didn't happen, and eventually realized it was because Tivo couldn't find a signal on those channels. The message on these channels is "Searching for signal on this cable channel..." This problem got worse over the ensuing days to the point where at least 25% of my channels wouldn't work. Then it plateaued and has not got worse. For example: ESPN on both standard and HD are both effected (38 and 724) Comcast Sports is effected in HD, but mostly working in standards (720, 40) Many channels Comcast Sports2 (721) work with no problems at all. I checked the signal strength of channels that are still working fine and it's around 40-43. Channels that are a bit fragmented around in the 30-35 signal strength range (standard def only, haven't found any HD channels that are fragmented; HD are either working fine or not at all). Channels that aren't working at all are 0 signal strength. My non-DVR Comcast cable box (which I once used for OnDemand access) works fine, in the same room. They split off from the same source cable, and I have tried both cords into he cable box with no problems at all. My Tivo HD unit in the other room works without problems, with all channels in the 40ish signal strength range. These are all units that have been working from between 1-3 years, and this problem is new. I have tried restarting my TIVO Primiere box, as well as re-seating the M card a few times. No help. Any suggestions or ideas as to what might be causing this issue?