Thanks to the MKV specification and the usage of a certain part of that specs by the release group IMMERSE many Mediaplayer vendor had to update their devices with a new updated firmware where they follow the spec. When not following and using a TV series release from IMMERSE there was suddenly no sound anymore (and: I noticed that with those MKV’s they already put english subtitles as well).
So after getting a notice, the guys at Conceptronic (I am not part of Conceptronic anymore, so do not blame me when you have an issue) jumped to their developers and after debugging and testing a first release fixing this issue was released today.
Find here the firmware for the CFULLHDMA