I too have (had) the same issue.. Apparently the samsung player isn't smart enough to route netflix sourced sound out the optical port. I had to use the analog outputs and connect them to the analog inputs of my AVR (also a Dennon). From this point on all is OK.
Well, I finally solved my Netflix connection issue by turning off my Belkin router's firewall.
Now I get the streaming picture but no sound??
I have the player connected to my Dennon receiver via an optical digital cable. Works great for playing DVDs so no idea where the N etFlix Sound is.
The pic quality is very poor also. I can only get 1.5G DSL so that apparently is not enough for a good pic. ( I also have a 1GB flash drive connected to the back as this is apparently needed for caching or something.)
Any thoughts on the sound issue? I checked all the connections and settings and it works fine for all except the NetFlix streaming.