I think cfg loader is up to v60 now, not that that will solve your issue for sure. I don't use that one so I have no clue. I DO use a western digital mybook essential iTB hd with no problems at all, after correct formatting. If your partitioning is done incorrectly it will not work. wbfs partition must be the first one listed in disc management, must be active, and primary.
With cfg loader I don't think you even need wbfs though, can run fat or ntfs.