ATT/Google allows you to reconfigure your homepage to your own liking. When I do this and save it, within about 24 hours, ATT will reset my homepage to include all the things I have removed. Is it possible to defeat a large but service-poor corporation?
So long as you're sure you clicked on Apply and OK when you made changes in Internet Options, they might be running BHOs to revert your changes. Can you go through the process again then close IE and restart the computer. If the change has not stuck then but changes again later, please post back.