http://bugs.winehq.org/show_bug.cgi?id=18876
--- Comment #4 from Vincent Povirk madewokherd@gmail.com 2010-06-05 13:29:28 --- GdipImageRotateFlip is implemented now, but it seems that for a value of 0 it's a no-op. So I'm inclined to abandon my earlier theory that it is at fault.
Could you get a +gdiplus log of this from the latest Wine?