Noise interference through speakers when using iTunes and web browser together.

I've got the latest version of iTunes (10.7), on Windows XP and I'm getting a problem when using my web browser (Crome) at the same time, If I scroll or move the mouse on the web browswer I get interference through the speakers (which I don't get if moving the mouse or scrolling on iTunes), any ideas as to why this is happening and how I can fix it please?

I can give more info with regards to sound card/speaker set up if required.