I still think you may have a malware issue....When I downloaded IE8 the first time something piggybacked on the download and I had the same slowdowns, with repeated .dll issues which had IE continuosly asking to close. I removed the virus, and went back to IE7., and the problems went away.....Finally, while away for a week of fishing, I returned to find IE8 had installed with an automatic update, and it's been running fine ever since......What AV scans did you run?.......consider running the scans in the virus and spyware
forum ....... Be sure to run only one real-time antivirus progam at a time.