Why does my mesh have a light area?

My mesh has some lighter color polys on it (see picture). They are exactly where the stairs are. They also appear in blender. Vertex and face normals are correct, and it is correctly unwrapped.

It is a smoothing group problem. You need to readjust the smoothing groups in Blender(i dont use blender so i dont know how to do it, but there must be tutorials out there.)

ok i fixed it. thank you very much for the quick reply and for the help.