Weird object lightning

Hello guys! I have a weird problem with my corridor i created for testing, it’s a simple corridor made with a single plane in Blender, collision works great and all, but the lighting is not as i expected… Is seems like it recognize only one side of the mesh and not the other, creating some weird artifacts with the lighting… I tried to duplicate the whole object and flipped the Normals in Blender… Worked, but it also made some weird artifacts with the lighting, and i don’t want to create additional polygons as it may reduce the performance and it’s a pain in the *** for me to do the UV Mapping…

Hope anyone can help me with that… I just want to make a simple corridor…

Pictures: http://imgur.com/a/hI6x5

Regards.