Make sure that you systems are totally up to date and that IE is the latest version - IE8. They should be Vista SP2 and XP SP3. If they aren't up to that level yet there is help and advice here for Vista SP2: http://community.mcafee.com/message/6648#6648 and here for XP SP3: http://community.mcafee.com/message/6631#6631
I gave you your own thread as yours is a slightly different issue and always best to start a new thread.
If the problem continues please post exactly what operating system and service packs you are using and what McAfee products and version thereof.
I finally gave up and decided to live with the problem. The weekly McAfee autoscan still worked. The computer ultimately hung up and recovery was the only way out. It was a lot of work to re-install XP and all my software, but McAfee works normally again. Wish I could offer better news...
Well please note that the above patch is not the IEFIX one that was mentioned, this one is slightly different. The OP could try that.