http://bugs.winehq.org/show_bug.cgi?id=8854
--- Comment #12 from knan-wine@anduin.net 2007-09-02 15:52:43 --- One thought I've had is that in early directx, it was an allowed practice to stop listening to the windows message loop and only poll directx messages. Thus all the old games that show up in windows as "Not responding" and ceases to work when you alt-tab out of them.
That could perhaps cause this?