Provided that you have access to the Flash script, Flash & Javascript can communicate via the ExternalInterface class so you could implement a JQuery function that would be called from Flash when the movie starts playing.
in JQuery
function stopMySlider()
{
//your javascript code here
}
in Flash
import flash.external.ExternalInterface;
//your constructor
public function Main()
{
init();
}
// any function that would get the movie to start playing
private function init():void
{
ExternalInterface.call('stopMySlider');
}
If you don't have access to the Actionscript code, one solution could be to create a loader component in Actionscript. There are plenty of examples around so here's only a brief description of the code:
var loader:Loader = new Loader();
// add your event listeners here
loader.load( new UrlRequest('path to your swf') );
private function onLoadComplete(event:Event )
{
addChild( event.target.content );
ExternalInterface.call('stopMySlider');
}