I got the following model: http://doekewartena.nl/temp/sw_test01.obj
Which is kind of crazy. When I upload it to shapeways it tells me it is not manifold and it is unable to repair it.
I did remove all doubles. I fixed the holes I could find. I did the check with the 3d printing add on and there it is manifold. So now I have no clue of what to do next.
Is the model just to complex itself?