Embedding symbols from SWF file in Flex Builder AS3 application

I'm trying to import symbols from an SWF file into a Flex Builder AS3 application (not MXML, just plain AS3). When I do this according to the manual, Flex Builder gives me a whole bunch errors:

1172: Definition mx.binding:BindingManager could not be found.
1172: Definition mx.binding:BindingManager could not be found.
1172: Definition mx.core:IPropertyChangeNotifier could not be found.
1172: Definition mx.core:IPropertyChangeNotifier could not be found.
1172: Definition mx.events:PropertyChangeEvent could not be found.
1172: Definition mx.events:PropertyChangeEvent could not be found.
1172: Definition mx.utils:UIDUtil could not be found.
1202: Access of undefined property PropertyChangeEvent in package mx.events.

Here's the entire test application I'm using:

Code:

---

package
{
        import flash.display.Sprite;
        import flash.display.MovieClip;
       
        [SWF(width="800", height="600", backgroundColor="#000000")]
       
        public class Tester extends Sprite
        {

                [Embed(source='assets/gfx.swf', symbol='handSymbol')]
                [Bindable]
                public var handSymbol:Class;

                public function Tester()
                {
                        stage.frameRate = 30;
                }
        }
}

---

What's going on?