
So I got this scene and the main light is a bit behind and to the right of the camera. When I have all materials to say 80% diffuse and all the rest off, I get this:

As if the normals are exactly the wrong way around or so

When I tick "double sided" in material editor I get:

If I tick "smoothing" too, I get this result: (which is more or less similar when double sided is turned off btw)

Which actually makes sense.. is this a known bug? I couldn't really find it somewhere. I am using 1.7 OB 5, have viewport on shaded solid or similar and tried a bunch of other stuff..
I can live with putting all materials on smoothing... but am wondering if it is a problem with my scene or a known issue..