Error #2136

Hi
I am using
Flash 9
Flex SDK
Flash Develop

Here is the exact error I get in FD;

“[Fault] exception, information=Error: Error #2136: The SWF file file:///C|/Documents%20and%20Settings/Administrator/My%20Documents/import%20image/bin/importimage.swf contains invalid data.”

this is my Main class;

package
{
import classus.Grid
import flash.display.Sprite;
import flash.events.Event;

public class Main extends Sprite 
{
    public var grid:Grid;
    public function Main():void

    {
        grid = new Grid();
        
        addChild(grid)
    }
    
}

}

This is my Grid class;

package classus
{
import flash.display.Sprite;

[Embed(source = 'images/grid.png')]


public class Grid extends Sprite

{
    public function Grid() 
    {
        trace("why oh why wont you work?");
    }
    
}

}
Can someone possibly explain to me why this is happening or at least how to fix it.

Thanx