You also need to get a condom for IE; its a slut. Or better yet; practice safe surfing and lock it (IE) down and get Firefox.
I have McAfee and also have scanned with Trend housecall. Also Spybot, Ad-aware, etc.
Agreed I think you have a virus. Try some free scans and removal tools if you can't go back to a system restore point. Google the symptoms and you may get a quick fix.
This would be safe surfing with Internet Explorer.
I prefer to use FireFox and block all the pop ups, spyware, cookies, and Java scripts that can get you into trouble.
Good Hunting... from Varmint Al