Yup, the problem was med+skin editor... I had created the fake sprites manually in med using the face builder. Seems the skin editor dosn't like manually built faces from med.

I created a cube and merged vertexs to get a double sided flat square and this time it worked when UV mapping.
Thanks!



What I don't understand is why now some top parts of the grass are black (it changes depending on camera angle)... I don't use any shaders on this yet so I'm not sure if it's my fault due to something else?...