Hi there, I am fairly new user of macs. My first one I got at the beginning of this year. I've been having an odd problem. The ONLY headphones that work on my macbook are the Apple white headphones from my iPhone.... y'know, plug it in, it takes a few seconds, then switches to headphones. I hate the apple headphones, though. I have excellent Grado headphones and an amp, too. But whenever I plug anything (other than apple headphones) it just doesn't switch to headphones! stays on speakers.... ideas?