In the Audio section of the menu there is the Dolby Digital choice. On that menu you are offered three choices two of which are Dolby Digital and I think Dolby Digital+/Atmos. When I choose one of them the circle is highlighted but goes away when I exit from that menu section. How do I know that my choice is still active or that the C61 has reverted to the lowest status. PCM or stereo or something like that.