I've got my 1906 connected to Sky+ via optical and selected Dolby Digital in the Sky menu. When watching any tv the surround speakers of my 5.1 system sound really distorted. With some programs it's only noticable if you put your ear to the speaker, but with others it ruins the sound. I've tried various different settings, but the only one which gets rid of it is 5 channel stereo. I've selected Auto digital input on the 1906. Is there an option I'm missing to get rid of the distortion? Thanks!