I have changed the normals on the few relevant polygon-objects, but the problem hasnt gone away.

My right-part (the cluster of objects) on the pic, had correct normals from the start, but a new render shows even bigger oddities on that right-most part, than what was shown in the pic above.

hmmm?

I have checked most objects on the left-part, and the normals were correct with the detail-objects. It was only some of the "encasing"-poly-objects that had the normals the wrong way.

well well