Facts: TiVo HD - installed with Comcast service and cablecards since early days of the HD - no troubles like this before.
CBS is channel 5. The HD programming for channel 5 through Comcast is channel 1005 and has been so for about 6 months. The SD channel for channel 5 is 5.
I have 3 season passes on my TiVo for cable channel 1005 for Thursday night. When I got home and checked my Tivo, the shows scheduled to record on channel 1005 were actually changed to 5. The following Thursday's CBS shows were still on 1005 as well as other nights for CBS. The season pass was still on 1005. I have no clue as to why suddenly they were going to be record on 5. I changed them all and it worked. I just don't understand the mystery.