Speaker and Soundcard Question
 

Recently I've been experiencing some minor problems with my sound.

Most of the time the sound will be just fine, but sometimes (mostly with music) it will go up or down. The volume change isn't very big, but it's noticable, and can be annoying at times. My sound card is stock, and it's what came with my Dell when I got it back in '03. My speakers are a little newer. Creative speakers, so they should be fine, which is why I'm a little confused over this problem.