Problems with the camera in Luxrender

I have made a torch in Blender 2.49 and i want to render it. But when i do so, the edges of the plane are shown, whereas i have placed the camera in Blender in such a way that the edges are not shown. I have tweaked with some settings but i have never accomplished what i wanted.

At the top you will see the edges. (The pictures are too noisy i know). How can i correct them?
File: Torch2.blend (883 KB)

Doesn’t show that way in 2.57. I can see the plain correctly, although material settings didn’t work 100%.