Dark surface unchanged by light source changes I have 3 lamps on the scene (the one on the left has 0 energy):



The rendered surfaces are supposed to look like shiny metal.  However, there's always a dark spot at the top of the large light orange surface, apparently no matter how the scene is lit:



I've also tried flipping normals, removing doubles in the mesh, changing specular and diffuse, horizon color, and turning off receiving shadows.
Has anyone seen something similar?
It seems from your render that the black/dark part is a reflection of the background (the environment). Try adding a large diffuse white plane above/in front of your objects so that there is something there to reflect instead of just the empty blackness of your world. Make this plane invisible to the camera or use the compositor to exclude it from the final render if it gets in the way of your scene (or move it far enough away so it isn't in view of the camera).