Game does not respond after changing tabs.

When change focus from Nightingale to do anything else, the game stops responding to the mouse and keyboard. I can return focus to the game and i still hear sounds and see monsters moving in the game, but the pointer is on top of the window and nothing happens when using the keyboard. Using Alt+Tab does nothing.

If I res6tart the game it works fine until the next time I tab out or hit Enter to get a mouse pointer.