(unity pro) Lightmapping not behaving like unity Pro lightmapping

We have a basic scene with a plane, a box and an ambient light. There is nothing else in the scene except those elements. When I bake with some basic skylight settings, the result looks exactly the same as the result I'd get when baking on a unity free edition. Namely almost black aside from some AO. I've tested the scene on a colleague's workstation and there it works fine and comes out as bright as you'd expect.

I've tried reactivating the Pro license and reinstalling Unity.

Does anyone know what else I could try to get the pro functionality working correctly?

UPDATE: I tried using a pro element of the lightmapper, but then I get this error:

Directional Lightmaps require a Pro license. UnityEditor.DockArea:OnGUI()

FYI: I'm using windows 8 and Unity 4.6.3f1