http://bugs.winehq.org/show_bug.cgi?id=22735
--- Comment #1 from Henri Verbeet hverbeet@gmail.com 2010-05-17 08:21:02 --- Created an attachment (id=28037) --> (http://bugs.winehq.org/attachment.cgi?id=28037) patch
Please give this patch a try.
There is still a bug where the window offset relative to the bottom-left corner of the screen doesn't appear to be subtracted properly for front buffer blits. I didn't investigate that yet, but does there already exist a bug for that somewhere?