I currently use the old PS3 (fat), which means that I can only output DTS-MA and Dolby TrueHD in LPCM. When this happens, my receiver picks up the signal as "Multichannel" and I am unable to use certain functions such as night mode.
I think* night mode can only be applied to Dolby (whether DD, DD+, TrueHD). I believe it's not applicable to PCM, nor DTS-MA as bitstreamed, or even just DTS.
PLIIx will not attempt to engage unless you tell the receiver you have rear surrounds, whether you do or not.
That is an interesting tidbit!
Ok, I just looked and tested. Like I've always thought, matrixing works with mch PCM.
I looked into the menu, and there are only 8 sub-menus, go to #5 titled "Listening Mode Presets". Now for PCM, DD, DTS, DTS-MA, TrueHD, put them all on PLIIX if you want everything matrixed always. There is a different option called "Last Valid", which should give you more flexibility.
Try that and report back.
Myself, I'm not on the latest FW, but second to last with 1.06 as far as DSP is concerned, however, I believe that all FWs from the very get go could matrix it all.