If you are going to be fragging, I suggest to an optical mouse and use the PS/2 port not the USB.
When you get a new mouse also pick up a new mouse pad. I love the 3M Precise Mousing Surface pad. It is the best thing for both ball and optical mice. It is amazing on how fast and precise this surface makes any mouse.
I also hear of people adding vegetable oil on the surface for that extra slick surface during Frag Fests....wierd!