I was told that if I upgraded to the lossless formats (Dolby TrueHD.DTS Master), that my current 5.1 would be a problem if the movie was encoded in 6.1 or 7.1. For example, the if I didn't have any surround backs connected, the sounds would simply be lost. They are not mixed into the left/right surrounds or into a single surround back.

Was told this by the folks at Yamaha when I inquired about the Rx v-663 and when I called another large online company. I even called Yamaha back a second time and asked a different operator. The guy said all their receivers worked that way w/ lossless audio.

They all said it is not a problem w/ the normal DD or DTS but not the lossless formats.

Is this the case????????