I just finished uploading a new tutorial to gotoAndLearn() which shows you how to use SWF decompiling as a learning tool to see what Flash is doing behind the scenes to your timeline code. Some people think that the words ethical and decompiling have no business being used together in the same sentence but I believe otherwise. It is obvious that you should not steal assets or code directly and if you do, you will more than likely get caught and be exposed. But decompiling your own work can be a great way to recover lost FLA files. I have saved my ass numerous times using decompilers! There are many good decompilers out there but my favorite is Sothink and it is the one I demo in this tutorial.
Enjoy the tutorial!