Lately, my powerbook has had sound problems. When left alone with no use of sound for a while, it decides that it just won't have sound. When you adjust the volume, you can't hear the pop-ing or any sound at all. And the only way to fix it is to stick the headphone plug into the headphone jack and out again, tricking the PB into thinking that it's without headphones now and it needs to bring out the sound. It happens so often it's annoying, especially if I don't have headphones with me. Anyone know what's going on with my PB's sound?