Nick, you were spot on with the Flash. On regular simple sites, such as google.com, there is low CPU usage. I can even open 10 windows with google.com without the computer breaking a sweat. When I go to the customers homepage, www.ynet.co.il, it immediately goes crazy. I've tried uninstalling flash and going to the same website and the CPU usage is under control.
So what do you suggest I do? Flash is unavoidable on the net.