It's a known issue lots of people have. It's some change in the software that caused Dolby Digital streams to not be output correctly or something like that. Mine did the same, and I changed an audio setting to something else to get it working again. Look at audio setting changes and if auto detect, choose a different one, like manually choosing dolby digital, etc. Or sterero / PCM, or vice versa. I typically reboot the device after changing these settings every time as well, out of habit of having past changes on some other problem(s) not really taking effect until doing so.
