[fallen1]

part of it may be your connection. If you're on a shared connection, or some other program on your comp is accessing the internet, or about a hundred other possibilities, you're connection speed will fluctuate and may not be consistantly delivering enough info for your card to work with. I have a 7800GS and I've seen my FPS drop into the teens when McAfee decided to download a major update in the middle of a gaming session.