We have the same issues with the new (few months old) Tivo V6 box showing extreme pixelation and green tone.
This happened recently occasionally and now it's happening all the time. This can be replicated by switching off an HDMI link from the tivo to TV via a Blueray unit. The only way to fix the problem is to reboot the Tivo box, which takes up to 10 minutes. This is not really acceptable. There are no signal issues, since, on a reboot, the TV signals on all channels is very good. My suspicion is fatigue on HDMI decoder / output from the tivo box. Soft switching the box on and off does not work. Resetting the TV or Blueray unit also do not work! The previous Tivo box did not exhibit these issues with exactly the same cabling. The leads are in perfect condition, so no connection or cable degredation issues. The issue points completely at the box itself. Are there fatiguing components in the HDMI transceiver?