Web player connect to socket policy server problem

SocketPolicyServer use port 843. Our server use another port. In C#:

 if( Application.isWebPlayer ||
                 Application.isEditor ) {
                 Security.PrefetchSocketPolicy( ip, 843 );
                 Security.PrefetchSocketPolicy( ip, port );
             }

Web client from Unity3d editor work fine. Web player after build doesn't work. Error in web player log:

 SocketPolicyClient1: Incoming GetPolicyStreamForIP
 
 SocketPolicyClient1: About to BeginConnect to x.x.x.x:843
 
 SocketPolicyClient1: About to WaitOne
 
 SocketPolicyClient1: Socket connected
 
 SocketPolicyClient1: Socket error: ConnectionReset

Why second Security.PrefetchSocketPolicy failed?