I get this same problem. It is intermittent, and has happened once with a remote (www) connection attempt, and many times from the same pc (I only have 1 or 2 other people that use the server, so I run it and my MC window from the same pc. Had no problems with it until 1.4.2.). It usually (but not always) happens after I have been playing, and I disconnect while leaving the server running. When I come back, it responds with one of the messages above, and the server log shows "(player) (/IP Address) lost connection", while showing no attempt to connect, and giving no reason for the disconnect. Again, I have had no problems with it until the update, so I am reasonably certain it's not my firewall.
I get this same problem. It is intermittent, and has happened once with a remote (www) connection attempt, and many times from the same pc (I only have 1 or 2 other people that use the server, so I run it and my MC window from the same pc. Had no problems with it until 1.4.2.). It usually (but not always) happens after I have been playing, and I disconnect while leaving the server running. When I come back, it responds with one of the messages above, and the server log shows "(player) (/IP Address) lost connection", while showing no attempt to connect, and giving no reason for the disconnect.
Again, I have had no problems with it until the update, so I am reasonably certain it's not my firewall.