You seem to be pretty knowledgeable, so will pose this to you, or anyone who views this thread.
I was going to watch CSI-Miami last night (Monday 10/7) I went to Cox KMTV HD channel with my decoder switched on and the picture was in a 4:3 format. The decoder box showed an HD signal, but it failed to fill my screen. I have the 16:9 34XBR 800 and thought something was wrong with the set or decoder. I switched to HBO-HD and the picture filled the screen. I then tried Showtime, and the picture was filling the screen on this channel also. I again switched back to KMTV-HD and still had the black bars on each side. I had this problem one other time when I first got the set, but attributed it to not understanding how it all works.
I do not know if this helps, but will mention it anyway. I will try to be concise and to the point though. I have my Cox digital box hooked to video 1 using an S-Video cable. There is a high speed data link cable that connects from the digital box to the HD-Decoder. The Decoder box is connected with component cables to Video 6. When I watch HD I have to switch to video 6 from video 1. Usually I use the Cox remote to pull up the guide and go to the HD channels. When you hit select, a window pops up telling you to press the exit button to receive HD. I do that and then switch the TV to video 6. Normally, when you hit the exit button, the screen goes black and then I switch to video 6, but before I switch to video 6, I can hear the sound only. Last night, when I hit the exit button, my screen not only went black, but I lost the sound also (on video 1). When I checked HBO-HD and Showtime the sound remained on video 1 till I switched to video 6.
I probably should be posting this question in another forum, but felt that anyone with the Cox system here might be better able to answer this. I really do not know how many people there are in Omaha who use a decoder box, let alone on this thread, but thought I would give it a shot.
Thanks to anyone who might be able to shed some light on this. I have been watching for over a month now, and am still awed by the beauty and clarity of HD.