Internet Explorer 7 beta 3 problems?

Has anyone had any problems after installing the latest beta for IE 7? I had no problems with the 1st or 2nd beta. When I installed the latest version beta 3 I noticed right away when I ran IE my computer ran real sluggish. I also noticed in the task manager the cpu usage was up pretty high (don't remember exactly how high) during the loading of pretty much any page and stayed up for a while till I let the page idle for a couple minutes or so. I uninstalled it and am using IE 6 again. This is one of my junker computers which runs an 800 Mhz cpu and 512 MB PC100 memory but I would think should still have no problem running this. Even after uninstalling the computer is still a little slower than it once was but I'm pretty sure that was it.