http://bugs.winehq.org/show_bug.cgi?id=21492
--- Comment #9 from Stefan Dösinger stefandoesinger@gmx.at 2010-02-10 04:35:24 --- Nope, my guess was wrong. There's no multithreading, and the window is apparently not destroyed.
Can you make a +d3d,+wgl,+win,+synchronous log? The last flag will use synchronous X calls and may bring up more hints.