I dont know if this is because of my set up or not, but when people are talking in single player mode, I cant hear them if I'm not facing them. I was pretty sure that in CoD2 when I turned around the voices just moved to the rear surround speakers (which was really cool) I can't check very soon as I lent COD2 to my friend.
360 -> component and optical ->Yamaha V2700 ->HDMI -> TV
I got the Yamaha after I finished COD2 so the probem might be there
I also experienced this in Splinter Cell DA so Im thinking my receivers not set up properly
can anyone confirm that they are getting dialog through rear surrounds?