I am confused about using the 990 for 5.1 sound. When I used the AutoSetup feature it discovered that there were only 5 speakers (no SR & SL) and according to page 29 of the manual the back surround channels will be disabled - which they are. So...can I not use the 990 for 5.1? Do I have to buy two more speakers to enjoy HDTV and 5.1 sound or is there a way around this? If not....why not?

Thanks....Lonnie