sound issues !

solo 2 running vix 3 last build. been running great since bought in December last year. now in the last few days on the channels that have Dolby digital, they only work in stereo !! (using a denon amp optical)
so have done a restore on the image to an earlier date and it works , only for a few hours or until its turned off then i get up the next day and its gone back again.
could this be a software or is it a hardware fault ? i have to restore every day now !! i ran world of satellites where i purchased it from and they where rude and no help . they did suggest a complete wipe and to load Zeus 009 !
i dont really want to do this any ideas please .
Oh forgot to say tried the amp with other things ps3 ect and no issues.

Quote from cazuela

The reason for suggesting to update the image is because newer images have newer revised drivers etc.....
I would make a backup of the working image then try the most recent ...
it only takes less than making a pot of tea ....
if you dont like it ,,reinstall your working image

Will give it try thank you