V+ HD sound problem
 

Hi all I have the new samsung V+ box and have a problem with getting dolby sound on HD, when I go to settings and change the audio and display to optical sometimes it will set to the right setting on the hd channel. If I then swap to another channel and go back to the same hd cahnnel I have lost the sound, also no other hd channel works if I change to them. I have had an engineer round and he changed the box for another samsung but it is still the same, it seams that the box can not store the setting. Has anyone else got or had this happen and how did you fix it.
Colin