I have been looking to buy an LCD tv. I have found a nice 1080p tv but it will not accept a 1080p source (sounds dumb, but from my research this seems fairly common). It takes other sources (1080i, 720p, etc) and upconverts it to a 1080p signal. I want a tv that is 1080p and will accept a 1080p source. How can I tell by looking at it in a store or online if it will accept it? Thanks for any help.