Now I just got a Panasonic 46' 850u today and I set everything up as I did on my Samsung 46' 750 series LCD TV for the past couple weeks, however the 850u isn't responding to my Xbox 360's HD component cables. I tried both Component 1 and 2 in the back to no avail, and then plugged in my HDDVR box using some spare component cables I had laying around and it worked fine so I know the ports work fine. It works fine in standard definition with the RWY cables in any of the other ports but as soon as I set it to High Def it goes blank. Is this Panasonics sick way of getting me to buy an HDMI cable for my 360 or am I missing something?

What is the output resolution on your Xbox set at? The Panasonic 800u (and I'm assuming the 850u as well) doesn't support 1080p via component.

I had to remember the order of menus in order to get to the HD output settings and eventually got it to 1080i where it worked fine, and below. The 1080P setting as you said didn't work. Thanks for the help.