BUMP!
Sorry but I really wonder why this bug occurs on some Messengers. If posters of this thread detected what is wrong with their Messengers and solved the issue, please let them write it. If they use any patches, add-ons, let them write all of those, maybe some common add-on causes this bug
Because here, on a Messenger contented forum, someone said that MsgPlus!Live let people detect who sign in while appearing offline. I said them that was a bug of MsgPlus! and detection of appearing offline contacts was not possible but they don't seem they're convinced. I must suggest them something to get rid off this bug, because they really believe that they could detect contacts who sign in appearing offline.