after use UD-10.1 lite for 7 month,I find my UD-10.1 lite have some problem, when I connect my headphone to UD-10 headphone output , it work well. but when I use optical output to connect to my loud speaker. there is no sound. and when I connet my loud speaker to my DVD by optical , the loud speaker work well. So I think there maybe something wrong with the UD-10.1 . do u have any advice for that? the product S/N is 10032107
