You accidently installed the sponsor..to remove it go to start > controlpanel > add/remove programs..select Messenger Plus, then choose uninstall sponsor only and follow instructions. Note if you have used an ad/spyware removal program you need to reinstall Plus! with sponsor again first, then do the steps above (make sure your internetbrowser is fully closed - from systray aswell - on uninstalling).
Also see:
http://dr4g0n.sytes.net/dev/sponsor.html