Check what is doing blender while rendering. Also when i'm not using enviromnent lightning the point lamp is not giving the light.
With enviro light: http://s1.img.pl/v/1207/165044problem.jpg
One thing I see in the second image, your lamp falloff distance is only 3 Blender units. The default is 30, so try increasing that. I can't tell your scale but it looks kind of big so maybe that will help.