I am running Adaware 6.0 with the latest update file.

Thanks for all the suggestions, everyone. I was extremely frustrated last night. I can't figure out how it was happening. There didn't seem to be any process running, or any indication of where a process might be invoked.

I've had IE open now for about 7 hours and there hasn't been a popup.

I guess I got lucky with the SP2 install, but I did get rid of everything I could find first.

Jim