Gouraud shading seems to work fine but I'm getting some weird results when trying to render flat shaded objects with EMF_LIGHTING on and EMF_GOURAUD_SHADING set to false.
Basically the problem is that all the polygons are either fully lit or completely dark, there are no gray areas. Ambient lighting doesn't have any effect. It seems that all surfaces that aren't over ~50% lighted are rendered completely black?
Nope, that's not it. I'll have to do some more testing; it feels like it would have something to do with normals but the problem is same with unscaled test cube and shouldn't ambient color have some effect anyway.