http://bugs.winehq.org/show_bug.cgi?id=24679
--- Comment #11 from Yorik van Havre yorik.vanhavre@gmail.com 2011-04-05 15:46:10 CDT --- Just to make sure this problem was really specific to sketchup, I just checked with a windows version of blender under wine (blender is also capable of saving a snapshot of its opengl window), but with blender everything works fine...
So this is probably specific to the way sketchup does it.
If you have easy access to the sketchup developers, it might be interesting to see if any of them has an idea of something that can be tried on the wine side...