normal plane rotation

Hi all,

I'm trying to follow an example on the manual "Generative Algorithms" called "displacements" (pag. 52 on the english version).

As the example is based on a previous version of GH I had to adjust the definiton with the new components (especially the rectangular grid) but there's still one thing that doesn't work: the polygons placed on the normal planes on top of the lines have a strange orientation. I think that the problem is related with the component normal plane that seems to have an arbitrary orientation but I don't know how to fix that.

any idea?