Here the code that I use to spawn the loaders:

Code:
function LoadPics()
{
	_root.TotalPicsLoaded = 0;
	_root.TotalPicsToLoad = _root.aPics.length;
	
	// load pics from disk
	for (var z=0;z<=_root.aPics.length-1;z++)
	{
		_root["PicListener"+z] = new Object();

		_root["PicListener"+z].onLoadComplete = function(target_mc:MovieClip):Void
		{
			_root.TotalPicsLoaded++;
			if (_root.TotalPicsLoaded == _root.TotalPicsToLoad)
				_root.StartApplication();
		}

		_root["PicListener"+z].onLoadError = function(target_mc:MovieClip, errorCode:String, httpStatus:Number)
		{
			trace ("error");
		}
		
		_root.attachMovie("mcPic","mcPic"+z,1000+z)
		
		_root["mcPic"+z]._alpha = 0;
		_root["mcPic"+z]._x = 10000;
		_root["mcPic"+z]._y = _root.PicY;

		_root["PicLoader"+z] = new MovieClipLoader();
		_root["PicLoader"+z].addListener(_root["PicListener"+z]);
		_root["PicLoader"+z].loadClip(_root.Server+"pictures/"+_root.aPics[z].filename,_root["mcPic"+z]);
	}
}
PS: aPics is an array with the list of pictures to be loaded.