Debug IE / Signature error back

Hello--Well the computer was fine for about two weeks, but now the same popups are back about that Debug / Signature problem. I had her repeat everything I did like making sure that enable third party extensions was still unchecked. She then ran that new AVG antispyware that I downloaded to her desktop and also Adaware, and CCleaner. She tells me that it is an intermittant problem. Some days she does not get the message, and other days she does. Any additional suggestions are greatly appreciated. Mike