For the last month, my TiVo guide has been unable to get data on about 40 different channels. It can read most of the guide, but fails when the channels are in the upper HD range. It obtains the map data (channel number and channel ID logo), but the guide grid remains "to be announced". Comcast has been out here to the house 5x so far and can't figure out what's wrong. It's happening on 2 different units.. (1) Premiere and (1) HD regular. I've done the entire "guide setup" from scratch (twice) on each unit. The image above was when it was coming up from one of the guided setups. Does anyone know what could be causing this?