Issue with Presence broadcast not being sent?

I had a complaint from one from one of our clients today that one user appeared to be offline to everyone else on the shared roster. Only upon re-logging back in did he appear to available to everyone else.
I checked the logs and I can see the presence broadcast from the server to the user's jid with everyone elses address in the 'from' but I don't see the subsequent broadcasts of vice versa. Upon relogin though I see the proper order of events.
Has anyone encountered this before or a reliable means to reproduce it?