model is not being listened to

This is my first RL application. I kept this as simple as possible and I have gone though the documentation, but I can't see why this isn't working.

The application is trying to get data from a command and display it as soon as the startup is complete.

// MAIN
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
           xmlns:s="library://ns.adobe.com/flex/spark" 
           xmlns:mx="library://ns.adobe.com/flex/mx"
           xmlns:local="*"
           minWidth="955" minHeight="600"
           >
<fx:Declarations>
    <local:ThinSliceContext contextView="{this}" />
</fx:Declarations>

<local:ThinSliceView/>

</s:Application>

// CONTEXT
package {
import flash.display.DisplayObjectContainer;
import flash.events.DataEvent;

import org.robotlegs.base.ContextEvent;
import org.robotlegs.mvcs.Context;

public class ThinSliceContext extends Context {
    public function ThinSliceContext() {
        super();
    }

    override public function startup():void {
        commandMap.mapEvent(ContextEvent.STARTUP_COMPLETE
                            , GetCommand, ContextEvent);
        mediatorMap.mapView(ThinSliceView, ThinSliceMediator);
        injector.mapSingleton(ThinSliceModel);
        super.startup();
    }
}
}

// VIEW
<?xml version="1.0" encoding="utf-8"?>
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009" 
     xmlns:s="library://ns.adobe.com/flex/spark" 
     xmlns:mx="library://ns.adobe.com/flex/mx">

<s:FormItem label="Thin Slice:">
    <s:Label id="lblThinSlice"/>
</s:FormItem>
</s:Group>

// COMMAND
package {
import org.robotlegs.mvcs.Command;

public class GetCommand extends Command {
    [Inject]
    public var model:ThinSliceModel;

    override public function execute():void {
        model.data = "started";
    }
}
}

// MODEL
package {
import org.robotlegs.mvcs.Actor;

public class ThinSliceModel extends Actor {
    public var _data:String = "Initially empty";

    public function set data(d:String):void {
        _data = d;
        dispatch(new ThinSliceModelEvent(ThinSliceModelEvent.MODEL_CHANGED));
    }

    public function get data():String {
        return _data;
    }
}
}

// EVENT
package {
import flash.events.Event;

public class ThinSliceModelEvent extends Event {
    public static const MODEL_CHANGED:String = 'modelChanged';

    public function ThinSliceModelEvent(type:String, bubbles:Boolean=false
                                       , cancelable:Boolean=false) {
        super(type, bubbles, cancelable);
    }

    override public function clone():Event {
        return new ThinSliceModelEvent(type, bubbles, cancelable);
    }
}
}

// MEDIATOR
package {
import org.robotlegs.mvcs.Mediator;

public class ThinSliceMediator extends Mediator     {
    [Inject]
    public var view:ThinSliceView;

    [Inject]
    public var model:ThinSliceModel;

    public function ThinSliceMediator() {
        super();
    }

    override public function onRegister():void {
        eventMap.mapListener(eventDispatcher
                    , ThinSliceModelEvent.MODEL_CHANGED
                    , handleData, ThinSliceModelEvent);
    }

    private function handleData(e:ThinSliceModelEvent):void {
        view.lblThinSlice.text = model.data;
    }
}
}

What did I forget here?