I switched DVD players last night and went into use my avia disk and when i was testing the surrounds it would play sound from both L and R speakers when it played them both? Also in the subwoofer check where it counts down in MHz's it wouldn't work? I ended up going into the dvd options and it says PCM...when i switched it to bitstream then tried it again, it worked... What is PCM...What is bitstream?? What's the difference and why did it mess my settings up? Anyone know?