A couple of weeks ago, within IE8, most video and certain other objects like gifs and hypertext flash with horizontal bars flashing across the object. Some of this occurs while a page is downloading (gifs and hypertext) and then stops when completed while certain videos flash when played while others do not flash at all. Also, when using the scroll bar, the entire screen flashes in the same way, with random horizontal bars.
Dude, trust me just get firefox. Firefox is where IE7 got he idea of multiple tabs from. Ive never, never, or ever had any issues with Firefox. And lemme tell ya, ive been to some questionable sites . Its worth the 5 mins to download and setup.