I was having a similar problem, although my source was a Panasonic Blu-ray player. I tried turning off HDMI Control in the Sony receiver and all of a sudden, it started working correctly and displaying DTS processing and other audio types besides Dolby ProLogic through LPCM. It even appears to continue working after I switch HDMI Control back on.
My questions are, how did you know that would work and why does it work?
I don't actually use HDMI Control, but in order to access the pass-through-always-on feature in the receiver, you have to have HDMI Control turned on.