Why did adding these meshes to Prefab cause them to no longer be effected by lighting?

i’m not sure if this is an issues with the new update i downloaded today but i’ve never had this happen to me before. im working on making a hallway prefab section. everything is going great and rendering great until i add the objects to a prefab. the second i add it to a prefab 3/4 of the meshes turn black and no longer accept lighting. i have pictures below.
nothing is changed between these two pictures other than adding object to Prefab. Why is this happening?

[15401-screen+shot+2013-09-12+at+4.23.18+pm.jpg|15401]

[15402-screen+shot+2013-09-12+at+4.23.45+pm.jpg|15402]

Can you check the layers and make sure they are not being culled? If they are prefabs you may have changed their layer at some point