I received the 1.6.1 IMG sometime last night and the audio though the optical cable to my receiver is no longer usable. It cuts out about 2-3 times a second, sounds like a CD skipping. The audio over HDMI into the TV is fine so it's not all audio coming out of the box. I've tried the power down and pull the power plug reset method that did not make a difference. Any one else "fortunate" enought to get 1.6.1?
I don't know what digital coax is.
That is another method (besides optical) of delivering digital audio - it is an RCA connector labeled SPIDF (IIR).