Beta Client, screen flickers

After a game is over, nearly every single game, the screen flickers. Not my entire computer screen, just the client. Parts of the screen go black (little rectangles). Then I have to mouse over them which will make them re-appear, and then other sections will go black.

If I then start a new game, the issue continues through champ select and any other menus I get into.

The only effective way to get rid of it is to exit the client and log in again.