That's what I originally believed, that something wasn't being decoded properly. However, I noticed something odd the other day when powering up the playstation; there was no loading sound, nor was there sound when moving between icons on the menu. Coincidentally, this always seems to be the case whenever certain dvd's will not play sound. And yet, all games and blurays have always been audible. I did try changing the sound output between the PCM and bitstream, but it had no affect during the no dvd sound. To further add to the confusion, when doing the factory reset in a last attempt to fix the problem, the sound will return during the initial setup and continues to be heard when I turn the machine off and then back on again. But if the PS3 is off for more than 6+ hours, it then goes back to not playing the startup music nor the clicks you here while scrolling through the menus. This is obviously related to the no sound during certain dvd playback, since they both always occur simultaneously. This has been extremely frustrating to say the least, especially since I've had the thing less than two weeks, and I don't think I can even go and exchange it since it was opened. I'm almost certain now that it is a hardware malfuntion, but I am running low on options.