Blender Import - Diffuse Shader Lightning Errors

Hey Community, who can I solve this problem: If I import a model form Blender (FBX) there are many lighting errors:

http://img842.imageshack.us/i/castleg.png/

I did the Shadows with the Build-In Lightmap-Tool (for testing low resolution ;) )

Thanks in advance,

Sebastian

Recalculate your normals. It looks like you don't have your vertices split at hard edges.