http://bugs.winehq.org/show_bug.cgi?id=24294
--- Comment #5 from Jerome Leclanche adys.wh@gmail.com 2010-09-06 16:12:05 CDT --- (In reply to comment #4)
Non-programmer wild guess ;) There could be some graphical operation which should relay on clean buffer, but instead there is some garbage.
Of course i could be totally off, but this corruption remind me bug 22888.
I jumped the horse too soon on that bug; disregard my earlier comment.