I have 2 Roku Premiere Plus devices plugged into Pioneer Elite receivers via HDMI. While streaming episodes of Dr. Who from Amazon Prime, I noticed some of the audio appeared to be missing (mostly sound effects). I verified this by forcing the Roku into stereo mode, and the audio was there. Switching back to DD+ or auto detect left me with missing sound.
I'm trying to determine if this is an issue with the Roku, Amazon, the receiver...etc.