http://bugs.winehq.org/show_bug.cgi?id=26670
--- Comment #1 from Dmitry Timoshkov dmitry@codeweavers.com 2011-04-14 04:14:58 CDT --- The following commit is the source of the problem:
commit 61e50e15ba45ad54655f98619f5ef33917033165 Author: Alexandre Julliard julliard@winehq.org Date: Fri May 28 12:14:43 2010 +0200
winex11: Map zero-size windows and set an empty window region for them.