New video card problems?

I bought a Powercolor HD 2400 Pro for my Dell E310. It has done what I wanted which was allow me to play pretty much any game out right now such as Crysis and World in Conflict. However, as my gaming performance has increased drastically, just general use has gone down. Such as when I'm browsing the internet, scrollling down pages will do a refreshing motion downwards (like if you don't have drivers installed). I have tried Chrome, IE, and Firefox and they all do it, with and without smoothscrolling. Its not so bad on pages without much going on, but sites such as youtube, bungie.net, and others are terrible and my cpu usage is thru the roof. I have the latest drivers installed for XP and I have tried reverting the the CD drivers but nothing helps. Any ideas?|||Scan for Malwares, Virus etc?