No, this isn't some neck seam, this isn't a seam in the texture itself. What it is, is a seam in the models shading. Everything looks perfect in Blender, but in Skyrim/Creationkit where the light hits it causes one side of the UV seam to be light and the other to be dark, instead of the gradient shading that's supposed to happen. I can't figure out what's causing this.

pictures?

http://i109.photobucket.com/albums/n54/Juggernaut_FireEmblem/SEAM_zps53dce39f.jpg