Only works with one user

I have a content type that has two user reference fields. I expected to see a reverse link on both of their profiles to this content instance. In fact, that is why I am using this module...to provide a page that contains shared profile information for closely related users...either of whom can update the data. Unfortunately, this module does not seem to support this capability. Only the user that was defined second gets a reverse link. Is this a defect...or is this by design?