TextField won't display if parent is a child?

Hi!

I'm writing a new framework but I've encountered an odd bug. Whenever I add a class as a child to my main sprite, it doesn't display the class's TextField. Only if I add it as a child of the stage will it display.

Main.as (Highlighted as Java)

spirea = new World(this.stage);
                                spirea.addChild(new LoginForm(spirea));

LoginForm.as

public class LoginForm extends Sprite
          {
                    public var usernameField:TextField;
                    public var passwordField:TextField;
                    public function LoginForm(w:World) 
                    {
                              usernameField = new TextField;
                              usernameField.x = 200;
                              usernameField.y = 50;
                              usernameField.width = 200;
                              usernameField.height = 35;
                              usernameField.border = true;
                              usernameField.borderColor = 0x000000;
                              usernameField.type = TextFieldType.INPUT;
                              addChild(usernameField);
                    }
          }

World is an extention of Sprite with a shaded bitmap added to it for decoration. It's a constant throughout the game, as in it doesn't disappear. The present code doesn't work. If I don't make it a child of spirea, it will work just fine. However, if I do w.addChild(usernameField); in LoginForm.as, it doesn't work. Neither does a combination of spirea.addChild(new LoginForm(spirea)); in Main.as and w.addChild(usernameField);

Is this just the nature of TextField or am I doing something very wrong?