Looked through your file that you provided and did not see any glaring problems. Actually looks pretty good generally.
I did notice what looks like some remnants left over from a previous install of AVG so if you've performed an uninstall from the control panel you may want to also consider running the proprietary uninstaller found Link Removed just to cleanup the leftovers. I see it looks like you're currently running Avast and I haven't heard of that product causing any such problems.
Since the problem seems only to be impacting your installed browsers try running IE8 without addons, Click start, All Programs, Accessories, System Tools, Internet Explorer (No Addons), additionally consider returning IE8 to its' default...