I don't know what fd does, but at a guess maybe what you're missing is that tar includes all the files in directories you give it? So if you exclude 'foo/bar' but include 'foo' then foo/bar will be in your tar file.
What I do is basically tar cf ls ~ | grep -v $files_to_exclude but if you want to exclude something that isn't a top-level directory you'd need to get slightly more fancy.