Okay, So i have my Unibody Macbook Pro (late 2009) hooked up to external speakers (RCA Home Theater system with a standard audio cable). Everything works fine and there is no buzz or sound except for the music of course until I plug my printer in. I know the obvious solution is to unplug the printer when listening to music but the printer is shared and other people print off of it etc. and I was wondering if anyone knew why this happens. Any ideas or solutions (other than unplugging the stereo or printer). Thanks.