I don't know, not being a Mud Clone, but my guess it it's because guests need to post with some sort of regular user name. A lot of anonyous messages have been deleted recently, some of them perfectly innocuous so I don't think it's content-related. Pick a name for yourself and try posting with it consistently, and see if this keeps happening. Also, non-music threads need to stay below the line (I mention that because I think I just saw this thread up at the top. Could be wrong though.)