I have a pair of Event TR-8s that are connected to my Powerbook G4 and they emit a very audible hiss (like exagerated tape hiss) when I have something connected to my Powerbook's FireWire ports. As soon as I disconnect the FireWire cable it goes away. I have an external FireWire HD that hosts some of my sample and audio libraries and need to have connected while I work. Speakers are connected to computer's 1/8" audio/headphone jack via a 1/8" mini to RCA "Y" cable. Does anyone know what's going on? Any suggestions and pointers would help. Thanks!