multiple messages

Hi,
 
I have been testing beep by flooding the session with messages and get SEVERE errors. I use a message listener that just sends a string back. On the sending peer's side I register the NullReplyListener. I do not wait until I have recieved reply before I sending the next message. After a few messages have been sent then I get a error
          SEVERE: Incorrect message number: was 16; expection 1
Is it correct to assume that I can send miltiple messages on a single channel without waiting for a reply between every message?
 
If I don't send any reply back then the error does not occur.
 
I have attatched a demo program to illistrate the problem.
 
Thanks,
Sean de Kock
 
Files:
    bombClient.java (package: org.beepcore.beep.example) - client
    bombServer.java (package: org.beepcore.beep.example) - server
    TestBombProfile.java (package: org.beepcore.beep.profile.test) - profile