Alt-Tab Client Freeze

When loading into a game, using the Alt-Tab hotkey causes the client to freeze. It cannot be removed from whichever screen it is being displayed on. I have been unable to remove it by any means except for a full machine restart. Obviously, this is incredibly frustrating. This can be easily replicated by Alt-Tabbing out of the loading screen just prior to a game. It is not a 100% certainty, but has happened to me three times now. During this time the game cannot by reloaded, ending the task can remove it (though this is impossible if using a single monitor) and there is not way to navigate out of the client. Force-closing the application will only result in a shadow-client still appearing on scree.