I'm sorry to say that this is a known issue with the ruby socket server and I haven't got a solution because I don't run the socket server.
Flash is going to be removed from chat completely in about two versions, and that means the socket server will be abandoned in favor of (probably) an optional node.js setup.
When you send a message, it will force and update to your list that doesn't require the socket server to be functioning. That's why when you send stuff, you see the update. If the socket server isn't running correctly (maybe because your client isn't listening to it) that's probably what will happen.
Note that recent versions of firefox require you to explicitly allow flash, and the socket server also requires it, so make sure you've got flash allowed (you should hear sounds).
Sorry I'm not helpful about it.