Try fixing this problem by troubleshooting it with Add-ons disabled - blogsdotmsdndotcom/ie/archive/2006/07/25/678113dotaspx (Replace the "dot" with a period ".")
You can also reset IE 8's settings by going to Tools > Internet Options, then the 'Advanced' tab, and then clicking the 'Reset...' button. That may work.
These instructions might solve your issue as well:
If you're not in Windows 7: How to troubleshoot Internet Explorer issues in Windows Vista and in Windows XP - supportdotmicrosoftdotcom/kb/936215
How to optimize Internet Explorer - supportdotmicrosoftdotcom/kb/936213
I hope at least some of this info helps,
MSFT Internet Explorer Outreach Team