I am seeing the same issue with Windows 7 now as well.
I have exactly the same problem. It's so bad that I have to disable the KIS protection for as long as I'm in any game because this KIS activity makes gaming impossible. It's really annoying and something that has appeared since I started using KIS 2010. I never had any of this kind of problem with KAV over the years. I never had any problems with KIS 2009 and games either. My system is very similar to yours. E8400 @ 3.0 GHZ with 4GB RAM (3.25 addressable), 1GB HD4850 and Windows 7 32 bit.