You don't state your McAfee application versions & operating system and service pack and version of IE but if it's IE7 or 8 (it should be the latter) go to Tools/Internet Options/Advanced and click Reset.
OK and prompts and click Apply and OK. Close and reopen IE.
Go to Tools/manage Add-ons and re-enable all the add-ons and see if that helped.
Also check for malware.
Download, update and run the free versions of these two tools and let them clean everything they find. reboot if asked to.
http://www.superantispyware.com/superantispywarefreevspro.htmlhttp://www.malwarebytes.org/mbam.phpAddendum: got your McAfee versions from your other thread so will move this thread.