I have my kd49xd7005 on the latest firmware hooked up to my 5.1 amp (sony by the way) via optical and have no problem with netflix or amazon playing movies etc in 5.1 audio.

I have just rented a movie from google play (end of year deal only 99p) but cannot get it to ouput in 5.1 audio.

Please don't tell me googles own ecosystem is worse on their own android tv than their competition.