When you use the custom setting to enable DD+, if the sound isn't encoded for DD+, the rear channels are dead and all you get is front L,C,R. The auto setting will allow all content to play, but it down converts the DD+ content to Dobly. It seems that the "auto" setting should include DD+ as an option - it auto detects all of the other formats so this shouldn't be that big of an issue. If not, the "custom" setting which implies that it down converts but just deadens 2 channels should auto detect all of them. I don't see the point of supporting a format if to activate it you have to degrade everything else. They should fix this.