Sound missing from loaded swf

1

I’m experiencing a strange problem. I have a .swf supplied from a client (let’s call it client.swf). If I play the stand-alone client.swf, the sound plays.

I have loaded client.swf successfully into my own project. The code I used to load client.swf is as follows:

var request:URLRequest = new URLRequest("client.swf");  
var loader:Loader = new Loader();  
 
loader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, loadProgress);  
loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loadComplete);  
  
function loadProgress(event:ProgressEvent):void {  
    var percentLoaded:Number = event.bytesLoaded/event.bytesTotal;  
    percentLoaded = Math.round(percentLoaded * 100);  
    trace("Loading: "+percentLoaded+"%");  
}  

function loadComplete(event:Event):void {  
    trace("Complete");  
}  
  
loader.load(request);  
videoHolder.addChild(loader);

videoHolder is an empty movieclip in my project. This is all that is in the file currently (one empty movie clip, and code to load client.swf into that movieclip). When I test the file, client.swf plays fine, but the sound is missing. Does anybody know what the problem could be?