I am confused about something. I noticed that certain shows in my to do list are 720p while others are 1080i. Now I record everything I possibly can in HD (as long as the network provides it of course) but I am confused as to why some of the recordings are 720 and others are 1080i. Is it a setting I need to configure on the TiVo box or does that have to do with the network specifically? *example- anything I record on CBSHD comes 1080i but anything on ABCHD comes 720p?