Hi, I just got a new IMAC running OS X 10.6.1. Let me start by saying i am not very computer savvy. When I go to an online forum where users occasionally post music videos, I click onto the video to see and hear it. An online window opens up and the video starts playing. The sound is full of echoes, and so is very distorted. When I close down the online window, the video continues playing on the forum page, and the echo is gone. How do I get rid of the echoing? I haven't yet transferred my Itunes from my old PC, so don't know whether I'll have the same sound problem. Thanks for any response.