Guy,
In JLinked -> Configuration under "Registraton & Login" there is a "Integrate into Joomla Registration:" setting. If that's disabled, it likely means that you overrode the login template before that setting was added and included the button yourself.
By the way, the setting name is incorrect (and will be fixed) since it refers to Registration when really its for login.
Hope that helps, but if not, let us know!
Alex