The cable!? I started to wonder about it, and then said "nah, it's an optical cable -- how could it be at fault?" Good info, kugumby.

Does the RP-56 have a coax digital out? I'm thinking that it's optical-only. If that is the case, a check to make sure the optical cable is solidly connected or (after the connection check) a cable change might be in order. The PDO from Outlaw is $20, a very good deal compared to the Monster opticals (as I've got a Monster optical sitting in "The Closet" -- where all computer spare parts, space cables, and other random stuff lives -- my wallet and I know well kugumby's pain on that count).