I don't know if anyone has run into this problem, but i thought i'd ask, and see if anyone could provide some help. I am running an Onkyo NR900 and Sony DVD player (DVP-NS400D) with an optical cable connecting them. I am 99.9% sure i have the Onkyo configured properly for 7.1 (i don't have problems running the Onkyo tests or playing music in All Channel stereo). The problem arises when i try to run the THX optimizer from the Star Wars DVDs - the 7.1 is all screwed up. the surround channels come out at the surrounds and surround back and the surround back channels come out through the centre channel. I am wondering if it is because the DVD player needs a 7.1 channel decoder built in (i.e. it's not THX certified), or does it have something to do with the Onkyo? Do i need a THX certified DVD player to get 7.1 discrete channels for the THX optimizer on the Star Wars DVDs to play correctly? any help is appreciated. cheers.