This is a video demonstrating how to use the Gaia Framework with a custom preloader animation instead of using the default preloader that comes with Gaia (called the "preloader scaffolding").
To learn more and to download the Gaia Framework, go here:
Create a new actionscript file for your custom preloader and alter the code as shown in the video.
Then, open the file Preloader.as (also in your Pages folder) and change this line:
public var scaffold:PreloaderScaffold;
public var scaffold:My-Custom-Preloader-Name-Goes-Here;
In Flash, click on your "scaffold" instance, and swap PreloaderScaffold for the name of your new class.