Oshyan, the extra '/' in the name of the texture in the MTL seems to be a by-product of the way DAZ|Studio exports their maps. Then, and this could hardly be seen as TG2's fault, when the imported object is converted to TGO the MTL keeps the same errant mapping. It's a simple fix for me, but I believe it is the exporter's fault (DAZ Studio in this case).
If this isn't enough info, let me know.