we´ve got a problem with our internal jive instance. Instant messaging doesn´t work at the moment! Every employee has a grey circle at the bottom-bar but you can´t click on it to change the status or something. So to my mind this means that the status is neither offline nor invisible. I already yet checked in the admin console whether Real-Time Conversation is disabled, but it isn´t.
I solved the problem restarting the Instant-Messaging Real-Time Tool via admin console. From that day on we hadn´t have any problems.