When I am connecting an optical cable from digital set top box to the 3300 AVR there is always an audio droupout of 2 seconds once in 10 or 15 minutes. Tried changing the cable but still the audio droupout is there. It is just like I hit the mute button for a second or two. There is not any problem with the Video. Tried resetting the set top box but still the audio droupout is there for couple of seconds in every channel. Any help to solve this would be greatly appreciated.