I seem to get this same problem. Sometimes, I hit the send button, it says it's sending the message, then the green sent message banner never appears and it just sits there with my message staring me in the face. If I hit send again, it just does the same thing and never sends. If I log out, log back in, and create the message again, it will almost always send (but not always). I've been able to repeat the "bug" under IE and Firefox (1.x version and 2.0).