http://bugs.winehq.org/show_bug.cgi?id=9333
--- Comment #6 from Ed Centanni ecentanni@lsijax.com 2007-08-15 17:59:48 --- I have provided a stripped down version that demos the problem. If you remove the DragDetect() in the mouse move handler the problem goes away.
Works fine in Windows with DragDetect()