Having UVs on mesh screws normals...

Having UVs on a mesh screws normals, even if the uvs are not used. I use world space top down projection as uv coordinates, i want to use UVs for parts that are steeper (instead of triplanar projection) but when the mesh has meshUVs the normals of the topdown projected part get screwed(looking flipped somehow).


The image shows the mesh with MeshUVs and without MeshUVS, the Normals on the steep part look ok but the normals on the topdown projected part get screwed.

The steep part is lerped using the mesh normal (not perturbed ! )... the lerp does not reach the flat part, so its not the normal map reaching the lower part.

here is the node tree..


I also tried to remove the 2 nodes that i want to use with mesh uvs to see if it also happpens when the mesh uvs are not used, and yes it also screws the uvs of the top down part. The problem goes away when the mesh has no UVs, but unfortunately i need UVs as triplanar is too expensive. 

pleeease help! :)