First of all, i've tried googling this, i've tried searching this forum and apple support for it but it seems i'm the only person who has this problem that i can find. or at least, the only person who is annoyed enough by it to ask for help. so, heres my problem.

when i'm watching a movie ( in Quicktime Pro 7.6, with the perian addon) whenever there's a low-volume part (with this i mean there's not much sound, but there is some. like low-key music) my mac decides to go completely quiet. Its either 4 or 5 seconds of sound below a certain volume, and it goes completely quiet until a louder sound pops up. i counter this by clicking the volume up/down buttons, apparently those noises are sufficient to knock it out of its utter silence, for another 4 or 5 seconds or until the movie itself starts making louder noise. so i guess its not quicktime thats the problem.

anyways, i cant find any settings that do this, and i'm at a point where i'm tired of having to click buttons to make loud noises in the middle of a movie just because there's nothing loud happening on the screen. (which does a really good job at ruining the immersion)

anyone know what this could be, or how i fix it?