I also noticed some audio issues. But I think it is related to the TV and the soundbar.
The issues I experienced only occurred when running in "native" mode. As I changed channels, the resolution would of course change as well, and 50% of the time, the audio would not get picked up and played. If i change the channel again and change it back, the audio would usually come back. Because of this, I am still running in 1080p mode, and haven't seen the issue. My first guess is that it is somehow related to the HDMI handshake that happens when the resolution changes, as I have HDMI going from the Ceton to a Toshiba soundbar, then from the soundbar to the television. But I am no expert.
Also, I do have occasional loud static pops and squeals when the audio stream first starts. Much work if I have bitstreaming turned on, but it is still there occasionally with stereo output. As i said, only as the audio stream first starts up for a channel.