I have this same problem. I have a new dell vista and have had this from the beginning. I have changed used three different virus programs...currently it's Avast....Also different spyware programs currently ist spybot. I had this happen with each of them. I don't think either is causing it.

I read somewhere it could be the OmniPage I use for my cannon scanner. I need the program so I can't uninstall it.

Every time I close an internet window even one that is functioning for me I get the pop up that says IE has stopped working.

I am also having the same trouble with Firefox.