What this might be?

[awol666]

Hi guys!
What is this problem about? Is it with normals or not? I have even applied normals modifier, to unify . But it did not help.

[ragupasta]

Have you deleted those faces and re-created them? Looks like different smoothing groups are applied to those faces. Or try selecting the vertexes and welding them incase there are overlapping unwelded verts.

[awol666]

Have you deleted those faces and re-created them? Looks like different smoothing groups are applied to those faces. Or try selecting the vertexes and welding them incase there are overlapping unwelded verts.

thanx! that was mess with smoothing groups, indeed!