I'll let you in on which one it was but not sure if you want it made public... Anyhow, I went to visit a sponsor's site and after a short time a popup came up, which I closed, then another and another shortly after... By the time I was done closing popups, all of my explorer windows were closed, including this one. I re-started the explorer, and now every 30 seconds or so I'm getting a spam in the form of a popup, so something got installed on my PC via one of the sponsor sites. I think it even does it when all of my explorer windows are closed. When I find out what this POS is I'll give more detailed info, I'll go find a spyware / adware scanner now.