Stopping FLV Playback in MediaDisplay/Controller?

CONCEPT

I have a pop-up flash movie that uses buttons to trigger two versions of a movie into a single MediaDisplay component.

PROBLEM

Problem is it will play both movies’ audio at the same time if the user clicks both bottom buttons before either movie has finished playing. See the example here: http://sassymonkeymedia.com/prototype/RootConcepts/.

I simply want to know how I can get the playback to stop on one movie when the other button is clicked. This way only one movie can playback at any one time.

FURTHER DETAILS

I tried this double movie pop-up interface before using a default MediaPlayback component and did NOT have this problem (see http://swellsound.com/audio and click the Christmas Tree Blues link near the top). There’s no scripting involved here beyond simple timeline stop() scripts on key frames.

The main difference with the new project is that I had to use the MediaDisplay component as a container (for displaying the two FLV files) which is controlled by a custom skinned MediaController below it.

ATTEMPTED SOLUTIONS

I tried unload to get the FLV files to flush and mx.control.MediaDisplay.stop and …MediaController.stop to no avail both as scripts attached to the main timeline and attached to the MediaDisplay object and the Media controller object (not all at the same time though).

HELP!

Any help is greatly appreciated in this frustrating problem. Thanks!!