Flexible Rails problem

Hello everybody, i'm reading the book Flexible Rails, i'm in page 122 of the pdf, but the login page is not working, the error it gives when i try to login:

[RPC Fault faultString="HTTP request error" faultCode="Server.Error.Request" faultDetail="Error: [IOErrorEvent type="ioError" bubbles=false cancelable=false eventPhase=2 text="Error #2032: Stream Error. URL: http://localhost:3000/sessions/create_xml"\]. URL: /sessions/create_xml"]   at mx.rpc::AbstractInvoker/http://www.adobe.com/2006/flex/mx/ internal::faultHandler()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx \rpc\AbstractInvoker.as:216]   at mx.rpc::Responder/fault()[E:\dev\3.0.x\frameworks\projects\rpc\src \mx\rpc\Responder.as:49]   at mx.rpc::AsyncRequest/fault()[E:\dev\3.0.x\frameworks\projects\rpc \src\mx\rpc\AsyncRequest.as:103]   at DirectHTTPMessageResponder/errorHandler()[E:\dev\3.0.x\frameworks \projects\rpc\src\mx\messaging\channels\DirectHTTPChannel.as:343]   at flash.events::EventDispatcher/dispatchEventFunction()   at flash.events::EventDispatcher/dispatchEvent()   at flash.net::URLLoader/redirectEvent()

The methods used are:

From RoR:

sessions_controler.rb

def create_xml      self.current_user = User.authenticate(params[:login], params[:password])         if logged_in?             if params[:remember_me] == "1"              self.current_user.remember_me              cookies[:auth_token] = {        :value => self.current_user.remember_token,        :expires => self.current_user.remember_token_expires_at        }             end          render :xml => self.current_user.to_xml        else     render :text => "badlogin"      end   end

From Flex:

LoginBox.mxml

private function handleAccountLoginResult(event:ResultEvent):void {         var result:Object = event.result;         if (result == "badlogin") {           Alert.show("The username or password is wrong.","Login Error");         }         else {           dispatchEvent(new LoginEvent(XML(result)));

        }       }

<mx:HTTPService     id="svcAccountLogin"     url="/sessions/create_xml"     resultFormat="e4x"     method="POST"     result="handleAccountLoginResult(event)"/>

LoginEvent.as

package com.pomodo.events {   import flash.events.Event;

  public dynamic class LoginEvent extends Event   {     public static const LOGIN:String = "login";     public var user:XML;

    public function LoginEvent(user:XML) {       super(LOGIN);       this.user = user;     }   } }

Can anybody please help me?