I agree with kim, but I think it only works under Windows.  I faced the 
same problem and applied the same solution but it did not solved it 
(excuse me kim).  I'm using Linux 2.4.2-2.  What I found is that you have 
to modify the registerit.policy file from the book and add the following 
to it

grant {
    permission java.net.SocketPermission "*:1024-65535"
}

Please note that this is just to get the book examples running.

Sherwin