Screen switch + OK button

I play League on a Macbook Pro. When I switch screens (back/into game) sometimes the lol window is translated to the lower part of the visible screen. If I happen to advance/ get demoted or anything happens in the game that puts up an OK button I can't move the window any more. Therefore I must restart the client because I cannot press an OK button that is outside the visible screen. Please make the lol window movable even when there is an OK button on it. Thanks.