As Jakub mentioned, it's a feature. To elaborate, XMPP supports identifying your sessions with a Resource string, and giving each resource a priority. The benefit is that you can configure clients in various locations (home desktop, home laptop, work desktop, cell phone/palm/toaster) with different resources and priorities to specifiy which session should have messages delivered to it. What this means is that you can leave your home machine logged in, go to work, log in there, and have all messages automatically delivered to your work session (by giving it a higher priority), then when you signoff at work, the server will start delivering messages to the next highest priority session: your home session!