I am running an Onkyo TX-SR605 receiver with Onkyo 5.1 surround sound speakers. When I plug in my MacBook Pro via an RCA to 1/8" cable, the audio has a strange buzzing noise that is accentuated when I scroll up or down on web pages, open hard drive windows, etc. 20 second Sample of buzz: http://www.filedropper.com/20100215220919 I took in my MacBook Pro to the Apple store, and they said they could not reproduce the buzz and that my audio card/port appeared to be working properly. However, when I plug in my iPhone, or my wife's Macbook, there is no buzz and the audio works flawlessly. Also, my dvd player works fine without a buzz... Any suggestions on how to get rid of this buzz?? Is the guy at the apple store full of it? Any help is greatly appreciated! Thanks!