MatchError on BeanContainer

[phancox]

Lacking much understanding of Scaladin internals, I'm unsure if this is a bug or not. It relates to a MatchError when trying to retrieve an item from a BeanContainer and how these items are wrapped. Using Scaladin 3

private val cbxAssociation = new ComboBox {
  caption = "Please Select Your Association"
  nullSelectionAllowed = false
  description = "Select the association where you are registering these members."
  inputPrompt = "Association Name"
  width = 150 px;
  itemCaptionPropertyId = "name"
  immediate = true
  p.setContainerDataSource(new BeanContainer[Int, Association](classOf[Association]) {
    import com.googlecode.mapperdao.Query.{ select => dbselect }
    val a = SportZmanInternetUI.associationEntity
    val query = dbselect from a orderBy a.name
    val associations = SportZmanInternetUI.queryDao.query(query)
    associations foreach { association =>
      addItem(association.id, association)
    }
  })
  valueChangeListeners += { evt =>
    val selectedAssociationId = evt.property.value.get.asInstanceOf[Int]
    val association = getItem(selectedAssociationId)
    debug("****" + association)
  }

This code throws the following exception

Caused by: scala.MatchError: com.dtc.sportzman.internet.PayMembershipFeesPanel$$anon$2$$anon$6@5d63a2b3 (of class com.dtc.sportzman.internet.PayMembershipFeesPanel$$anon$2$$anon$6)
   at vaadin.scala.internal.WrapperUtil$.wrapperFor(WrapperUtil.scala:12)
   at vaadin.scala.Wrapper$class.wrapperFor(Wrapper.scala:8)
   at vaadin.scala.AbstractComponent.wrapperFor(AbstractComponent.scala:25)
   at vaadin.scala.Container$Viewer$class.container(Container.scala:151)
   at vaadin.scala.AbstractSelect.container(AbstractSelect.scala:31)
   at vaadin.scala.AbstractSelect.wrapItem(AbstractSelect.scala:86)
   at vaadin.scala.Container$class.optionalWrapItem(Container.scala:61)
   at vaadin.scala.AbstractSelect.optionalWrapItem(AbstractSelect.scala:31)
   at vaadin.scala.Container$class.getItem(Container.scala:26)
   at vaadin.scala.AbstractSelect.getItem(AbstractSelect.scala:31)
   at com.dtc.sportzman.internet.PayMembershipFeesPanel$$anon$2$$anonfun$3.apply(PayMembershipFeesPanel.scala:48)
   at com.dtc.sportzman.internet.PayMembershipFeesPanel$$anon$2$$anonfun$3.apply(PayMembershipFeesPanel.scala:46)
   at vaadin.scala.internal.ValueChangeListener.valueChange(listeners.scala:72)

Obviously the Scaladin code isn't prepared for this but I don't know where to fix?

def wrapperFor[T](maybeWrapper: Any): Option[T] = {
  if (maybeWrapper == null)
    None
  else
    maybeWrapper match {
      case mixin: ScaladinMixin => Option(mixin.wrapper.asInstanceOf[T])
      case interfaceMixin: ScaladinInterfaceMixin => Option(interfaceMixin.wrapper.asInstanceOf[T])
    }
}