Flickering in Safari

I've been getting a really bad "flicker" in Safari for about a month now. It seems to occur on websites where pictures, ads, and videos are layered in with the content. A perfect example is www.usatoday.com Upon loading the page flickers about 5 times. Then, when you move the mouse over all of the headline images it flickers on each one.

I've tried restarting the computer, reinstalling flash, disabling plug-ins. All websites are working perfect with Chrome and Firefox. Any ideas?