Adobe it’s planing to release a security update for flash player, to protect of cross side scripting and other vulnerabilities what have the swf format, this changes going to affect any new app developed and older content also (also the content for flash player 7), to prevent the broke of your app, need to have some precautions what are detailed in this document:

http://www.adobe.com/devnet/flashplayer/
articles/flash_player9_security_update.html

Read it and make your change before you app or content dont work anymore :p

Regards,
Shadow.