This is a very rare bug and we are aware of one workaround, thanks to one of our users. While the game does not allow Alt-TABbing, you should be able to switch to the Task Manager and then go back to the game - this should allow the movies to render properly.
You can launch the Task Manager in two ways:
Press Ctrl-Shift-Esc, or, if that doesn't work,
Press Ctrl-Alt-Del and click on Task Manager.