HELP! - Can't get PS3 to output 5.1 on Blu-rays or DVDs

Ok, here's my setup:

PS3, XBOX 360, DirectTV HD-DVR all plugged into a Bravia KDL-55NX810 with HDMI. Digital Audio out from TV to Sony HTIB (HT-SS360).

I have each component going to the TV with HDMI so that the 3d video signal can make it to the TV since my HTIB doesn't support pass-through, otherwise I'd have it all hooked up through the receiver first (like I used to before I got this TV).

On my Xbox, when I load a DVD or a game, my receiver displays that I'm getting 5.1 channel sound and it works fine (Dolby Digital 5.1, in case that's important).

On my PS3, I get 5.1 channel sound when I play a game, no problem.

HOWEVER, when I try to play a DVD, Blu-Ray, or 3d Blu-Ray on the PS3, I can only get 2.1 channel sound (no matter which audio output formats I have selected on the Audio Setup menu). I used to have no problems getting 5.1 from anything on the PS3 when I ran it directly to the receiver with HDMI. But since the Xbox does it, I know the setup is capable of handling it, so it's got to be a PS3 issue (right?).

This seriously bothers me, since this means that I can either have BD/3DBD video and no surround sound, or hook the PS3 directly to the receiver and get surround sound, but no 3d.

Any suggestions on how I can get my PS3 to output 5.1 sound on my DVD/BD/3DBD discs? I'm at the end of my rope and any help is appreciated.

I suppose I forgot to mention this in the original post:

My receiver only has 1 optical in port, so I can't run the audio from each of the 3 components directly to the receiver, nor can I run the other 2 to the TV and then to the receiver with the optical and then also connect the PS3 to the optical as well.

I do have an optical splitter/joiner, but that won't work because as long as the TV is on, it sends signal through the optical cable and the 2 will interfere even if i go that route.

I looked into a manual switcher, but that would pretty much defeat the purpose of the all-in-one remote I just bought. Thanks for the suggestion though!