Occasionally the sound on the TV, when using TiVo, is distorted. Switching the TiVo box to a different channel then switching back to the original channel usually cures it but it is irritating to have to do this frequently. Is this a box fault or just one of the idiosyncrasies of the system. This fault only occurs when using the TiVo box and not on other inputs to the TV. Anybody got any ideas??