Blu Ray Audio Channels on a PS3

[jpgl450]

I am completely perplexed after spending two days working on trying to get the audio channels to work correctly on my PS3 when playing a blu ray disc. I have the player connected via Component and Optical connections. I can play games or regular DVD's and I get a great 5.1 sound. When I play a Blu Ray disc I get the out left and right channels but no center or rears. I have checked to make sure everything is connect correctly and my audio is set up correctly on my Blu Ray menu settings. I had the tech support at Sony walk me through the set up again, but nothing.