I'm probably not doing something really simple! but here is my problem- My set up is- LG PX11 Plasma JVC THR3 all in one recordable DVD surround system.( amazing value by the way! ) Panasonic Digibox (5.1.B ?) I can get surround sound when I play a DVD, but can't get surround through sky. do I need a sky box with a coaxial or optical lead (a connection which my sky box dosen't have!) and connect it to my DVD system ?