Those textures lack _s versions of them.
viewtopic.php?f=21&t=9009
Based on what he said "even though the files are there." I'm guessing he has in fact created Spec maps for these textures. What that probably means is that they either aren't being converted correctly, or for some reason or other they aren't supported.
My only real suggestion is to go over your entire process, make sure every single detail from start to finish is correct as far as you know and try again. If nothing, share your process and let people pick it apart from possible errors.
That said, if Amoroth is right and you haven't created your own Spec maps, or converted the existing ones, do make sure to check the link he provided as this is a consistently raised topic on the forum, and there's plenty of support to trawl through.
