automatic push in vaadin + scala makes me waiting

General
1

hello
I would like to perform a simple change of the text of a label, using vaadin 7 & scala.
here is my UI:

[code]
package com.example.scaladinchat

import com.github.nscala_time.time.Imports._
import vaadin.scala.UI
import vaadin.scala.VerticalLayout
import vaadin.scala.Label
import vaadin.scala.server.ScaladinRequest
import vaadin.scala.Button
import metier.Objets.Rdv
import models.{ oracle => myOracle }
import vaadin.scala.PushMode

class N02Parameters extends UI with myOracle { app =>

pushConfiguration.pushMode = PushMode.Automatic
val l = Label(“zigouigoui”)

def changeLabel{
access{
l.value=“roploplo”
}

}

override def init(request: ScaladinRequest) {

content = new VerticalLayout {
  add(l)
  val b = Button("Click me!", { e =>
      changeLabel
  })
  add(b)

}

}

}
[/code]but when I call the page, there is at the top-right of my window an waiting animation, and I wait but nothing happens.
can you tell me what’s going wrong?

thanks

olivier