At the very least I would think the player would pass the lossy DTS 5.1 audio track (if available), otherwise your option is to let the player decode it to multi channel PCM which should work.
Originally Posted by vince217 /t/1415276/is-this-normal-receiver-not/0_50#post_22125208
Optical connection from Blu Ray (Sony BDP-S570 if it means anything).
Tron:Legacy doesnt have a 5.1 DTS track (nor english 5.1 Dolby). So in order to listen to it in surround, I had to listen to it in French or Spanish!
I guess it is just my receiver getting a little long in the tooth then!