http://bugs.winehq.org/show_bug.cgi?id=12599
--- Comment #2 from Lucas Murray admin@undefinedfire.com 2008-04-27 08:22:37 --- After playing around they look to be different bugs. Bug 12449 causes the bottom part of the windows to remain gray even when moving the window upwards, this bug has the bottom parts of the windows completely unpainted (When I drag another window on top of it a ghost remains, bug 12449 has no ghost) and when the windows are moved upwards they get painted.
I have attached a screenshot of both bugs occurring at once.