Triggers and custom animation - pausing video & audio

I am using Powerpoint 2003 and Windows XP.

Some of my inserted video files can be paused or restarted just by clicking
on them. Others will onlyl restart when I click on them. When I look at the
Custom Animation menu, there is a trigger for pausing in addition to the play
command listed for those files which indeed are pausable during the slide
show. How do I create that set up for files that won't pause?

Is there any way to do this for inserted sound clips without inserting the
media player as an object