If the Pioneer has a "pass through" mode, you might try that, and/or if you can turn off "deep color" on the Tivo, it that option is available. Usually the video dropouts are a result of a hdmi cable that isn't able to maintain the signal strength needed. 3d signals over 20' can start to get a little dicey if your using a lower thickness cable, like say 26 awg. Each connection in the hdmi chain can cause a slight signal loss. Maybe running the connection through the Pioneer is degrading the signal, just enough, to cause the dropouts?