Whose the smartest can figure this brain teaser of AS 3.0 problem?

Question

Spent all afternoon trying to figure out the following AS 3.0 problem in Flash CS4.  I can load an image using a custom class (called "BitmapExample") inside a unnamed package by placing the class name in Class field in the Properties panel inside of Flash, everything works fine.  The image and the .as file are in the same folder as Flash file.
The following is the code that reside in the "BitmapExample.as" file:
package {
       import flash.display.Loader;
       import flash.display.Sprite;
       import flash.net.URLRequest;
       public class BitmapExample extends Sprite {
                  private var url:String = "Image.gif";
                  public function BitmapExample() {
                        var loader:Loader = new Loader();
                        var request:URLRequest = new URLRequest(url);
                        loader.load(request);
                        addChild(loader);
BUT!!  If I try to access the class file by 1) removing the name from the Class field in the Properties panel 2) Using the main Actions panel (F9) in Flash instead (in frame 1) and use the command:
var testLoad:BitmapExample = new BitmapExample();
I can access the class (I placed trace statements to double-check), but I CANNOT get the image to load using this method.  Trust me, it's not a typing error (even if above is mistyped), I played around with it all afternoon.  I could even take the applicable code from the *.as class and place inside the Flash ActionScript panel and get it to work.   Anyone should be able to take the above code and rename a gif file to duplicate the problem.
So bottomline: Why is that I can run an AS 3.0 class (that loads a picture) using the classname in the Properties - Document field, but NOT be able to load the same picture(though I can access the class) by creating an instance of the class in the Flash Actionst panel (F9) (you have to remove the class name in Properties - Document field for this method).
Trust me on this one, you'll have to run the code to probably know what I'm talking about.

Answer 1

Turns out you were right!  Thanks so much......
So for those viewing this question, it is actually quite helpful, the point is:
When you enter a class name via the Properties panel - Class field in Flash CS4, it turns out Flash will not only access the class but will instantiate an instance of the object of that class AND add that object to the Stage as a display object.    On the other hand, if you use the Actions Panel (F9) you must manually 1) create an instance of that class 2) and add it to the Stage as a display object if you are going to use code and see any visible results on the Stage
var testbat:BitmapExample = new BitmapExample();
addChild(testbat);