The Tivo schedule for ABC (WPLG channel 10) in Miami, FL is missing information for two full days. The schedule jumps from Friday 12/1 at 6:30 PM to Sunday 12/3 at 7:00 PM. This makes it impossible to schedule TIVO to record any programming for this channel during this time period. Since college football games are played on Saturdays, I guess I won't get to see the ACC championship game. This only appears to be an issue on ABC channel 10 and its HD counterpart channel 431.
Comcast controls the channel lineup, but the Tivo guide is provided by Tivo, and it's up to them to correct any errors. Check out Tivo's Channels Missing or Incorrect in Live Guide: Troubleshooting and Report a Lineup Issue pages.