Pong game problem

Hi,

I am using the pong game from the following tutorial in my own fla file:

http://www.kirupa.com/developer/actionscript/pongout.htm

I have other elements in my fla document such as a volume slider and other buttons. When the game is running it is not possible to use these elements, they appear to be locked. It’s as if the game uses the entire stage and nothing else can be selected.
Is it a case of setting some boundaries for the entire game in the .as files?

How can I prevent this?

Thanks