sproutcore issue - availableList contentBinding crashes app

main.js

/* ... */

  var items = Items.store.find('Items.Item');
  // Don't need this
  //Items.selectedItemsController.set('content',[]);
  Items.mainItemsController.set('content', items);

/* ... */

main_items.js

//Don't need this and shouldn't probably ever have to have controllers dependent on each other
//sc_require('controllers/selected_items');

Items.mainItemsController = SC.ArrayController.create(
/** @scope Items.mainItemsController.prototype */ {

/* Don't do any of this  --v
  selectedBinding: 'Items.selectedItemsController.arrangedObjects',
  arrangedObjects: function() {
    var sel = Items.selectedItemsController.get('content');
    return  this.filter(function(item) {
      if (sel && sel.get('length')) {
        return sel.indexOf(item) === -1;
      } else return YES;
    });
  }.property('content', 'selected'),
  selectItem: function() {
    var selected = this.get('selection').get('firstObject');
    console.log(selected);
    Items.selectedItemsController.addObject(selected);
  }
*/
});

main_page.js

// ==========================================================================
// Project:   Items - mainPage
// Copyright: @2012 My Company, Inc.
// ==========================================================================
/*globals Items */

// This page describes the main user interface for your application.  
Items.mainPage = SC.Page.design({

  // The main pane is made visible on screen as soon as your app is loaded.
  // Add childViews to this pane for views to display immediately on page 
  // load.
  mainPane: SC.MainPane.design({
    layerId: 'items',
    childViews: 'availableView'.w(),
    layout: { width: 400, height: 300, centerX:0, centerY: 0 },
    
    availableView: SC.ScrollView.design({
      contentView: SC.View.design({
        layout: { maxHeight: 200, top: 0 },
        childViews: 'available selected'.w(),
        available: SC.View.design({
          childViews: 'availableLabel availableList'.w(),
          availableLabel: SC.LabelView.design({
            displayTitle: "Available Items",
            value: "Available Items"
          }),
          availableList: SC.ListView.design({
            textAlign: SC.ALIGN_CENTER,
            rowHeight: 10,
            columnWidth:300,
// oneWay binding is preferred for content anyway, since it is faster and the listview can't alter
// the content.  The selection binding should be two way since the listview alters it.
            contentBinding: SC.Binding.oneWay('Items.unselectedItemsController.arrangedObjects'),
            selectionBinding: 'Items.mainItemsController.selection',
            contentValueKey: 'name',
            target: 'Items.mainItemsController',
            action: 'selectItem',
          }),
        }),
        selected: SC.View.design({
          layout: { top: 100, maxHeight: 200},
          childViews: 'selectedLabel selectedList'.w(),
          selectedLabel: SC.LabelView.design({
            displayTitle: "Selected Items",
            value: "Selected Items"
          }),
          selectedList: SC.ListView.design({
            textAlign: SC.ALIGN_CENTER,
            rowHeight:10,
            columnWidth: 300,
            contentBinding:'Items.selectedItemsController.arrangedObjects',
            // This should allow you to select an item here to move it back
            selectionBinding: 'Items.mainItemsController.selection',
            contentValueKey: 'name'
          })
        })
     })
    })
  })

});

selected_items.js

Items.selectedItemsController = SC.ArrayController.create(
/** @scope Items.selectedItemsController.prototype */ {

  contentBinding: 'Items.mainItemsController.selection',
  orderBy: 'name'

}) ;

unselected_items.js

Items.selectedItemsController = SC.ArrayController.create(
/** @scope Items.selectedItemsController.prototype */ {

  contentBinding: 'Items.mainItemsController.selection'.transform(function(selection) {
    var arrangedObjects = Items.mainItemsController.get('arrangedObjects');
    
    // create inverse of selection
    selection = selection.copy();
      
  }),
  orderBy: 'name'

}) ;