I have one user whose status is not visible by users that are connected via Federation. Users within the same cluster can see his status normally. And he can see others, both locally and across a Federation connection. However, when someone in another Federation adds him, they see nothing. No error, no blocked symbol, just a grey ball. I can see nothing different about this user, other than the fact that he is the only user in the organization using Vista (everyone else is XP or Win7), but I have logged him into a different computer and the same thing happens.
Under Privacy | Manage Domain, all Federated Domains are set to Ask. When others add him, he gets no notification. So I'm at my wits end. And this is the only user that is desplaying this problem.