I'm using my first TiVo (Premiere XL4) and I have a few questions after using it for a couple of days: 1) Some of my guide listings are empty. Why is that? I'm using a cable card and it seems to be working fine, and 95% of the guide is populated, but certain channels or even certain items are just blank for seemingly no reason. I've forced a TiVo network update and they are still empty. 2) TiVo suggestions are really neat, but I don't want it to record any SD programs or any SD channels. Is it possible to customize this?