help with onkyo and ps3

[kneebone]

I am going nuts with this. I hope someone can help me. Im have PS3 hooked up to a onkyo 605 with a HDMI 1.3 cable. I have changed the audio settings on the PS3 some many times. I think I used every possible combination there is. bitstrem , pcm, all the 7.1 on , all the 7.1 off, some on some off ....... bla bla bla . I still cant get it to play a BluRay in 7.1(Shoot em Up is a 7.1 disk) I can only get it to play in 5.1. I know that it is a very easy fix but i cant seem to get it to work. any help would be grate. Thank you Danny