Sorry, Moure. I never wanted to say that your little child can't render awesome pics.
LuxRender is amazing. That's why I am here.
The point is that, as far as I remember, I am doing the same thing as before, but getting uglier pics. So I thought it could be some kind of config I needed to do. Maybe a change in the behavior of the render, in the new 64bits version, or in the blender 2.5 exporter, dunno. There are many things that can change and will force you to adapt to get the same results.