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?