OP: most TV's have something where you can see what kind of signal the TV is getting. For example, on mine, if I hit the info button on the TV remote, it tells me 1080p. Do you have something similar? What Im after is...are you sure the TV is getting the proper signal?
Also, are you using a receiver?
My system: Yamaha RX-A3060, Emotiva XPA-2, Salk Song3, Salk Songcenter RT, Polk FXiA6, Rythmik FV15HP, Intel i7 HTPC running JRiver Media Center