I have a Toshiba SD-5970 dvd player with HDMI. When listening to audio cd's there is a scratchy type of distortion in the sound. This only happens, however, when I listen to a CD, not with a dvd. And only when using digital sound output (tried both coax and optical and I still get distorted sound). Analog L/R cables work fine and give off no distortion whatsoever. Any ideas as to what the problem could be?