Random Blank Task Box...,

....shows up in my taskbar and causes any game that I am playing to minimize and I get thrown to my desktop. It does not minimize IE while I am online. This blank task box shows up for 1 second then closes automatically. This anomoly??? started to appear after I downloaded/installed the automatic update from MS (I have Windows XP home SP2) that contained the Malicious Software Removal Tool. I uninstalled the update (all of them) but the problem continues (I have since reinstalled the updates). I completely disconnected my computer from the net to see if it was being generated by something/someone online but it occurs both on/offline. Mcafee Internet Security Suite has been installed on my computer since day 1 of my Cable service and has been updated continuously with my Firewall settings on "Tight" I fear that something/someone is taking screenshots of my current screen. Has anyone run into this??? Any ideas/help would be great....Thanks in advance...Bootlegger267