Make sure you have SPID turned on in the setup screens. Should be though if you are passing normal audio through the port. I have mine connected to a Sherwood receiver via optical and all works fine for me. All the
PBS channels pass audio as well as the AC-3 channels on G10R (Spanish language). I will say this much as to the Sherwood there is some setting in it that kills the optical port. It is an audio setting. I can show the audio set to O1 (Optical 1) but no signal being passed. Playing with the output options got audio back when this has occurred.
Perhaps your Extigy just needs reset. I know I chased the problem for a day before finding it. Thought the cable was bad then perhaps the receiver (Sherwood) then started playing with buttons and all of a sudden sound.