ho fatto una prova, ovvero: invece di caricare l'swf con loadmovie, ho creato un movieclip all'interno del quale ho inserito i frame dell'swf che volevo caricare, e ottengo lo stesso errore. se invece inserisco i frame direttamente nello stage, tutto va bene.
le azioni sono:

frame1
codice:
#include "mc_tween2.as"
Stage.showMenu = false;
Stage.scaleMode = "noScale";
_global.playStat = "";
_global.p = 1;
_global.total = 4;
_global.times = 0;
_global.gg = 0;
_global.galleryNo = 0;
_global.howmany = 0;
_global.should = 0;
///////////////////////////////////////////////////////////
// EDIT BELOW THIS LINE
var slideTime:Number = 2; //Seconds each slide displays for
var folderPath:String = "http://www.lewi-p.co.uk/xmlReader/"; //Change to desired folder
var emailStat = false; //Enable email function, true/false
frame2
codice:
this.onEnterFrame = function() {
	if (_root.getBytesTotal() == _root.getBytesLoaded()) {
		this.onEnterFrame = null;
		gotoAndStop("loadXML");
	}
};

frame3
codice:
stop();
var arrMenu:Array = new Array();
var arrItem:Array = new Array();
//
function loadXML(loaded) {
	if (loaded) {
		var xmlRoot = this.firstChild;
		_global.galleryNo = xmlRoot.childNodes.length;
		for (m=0; m<galleryNo; m++) {
			_global.items = 3;  //numero di elementi
			arrMenu.push(xmlRoot.childNodes[m].attributes.name);
			for (i=0; i<items; i++) {
				var descString:String = unescape(xmlRoot.childNodes[m].childNodes[i].childNodes[1].firstChild);
				//Uppercase Main Title
				var xString1 = unescape(xmlRoot.childNodes[m].childNodes[i].childNodes[0].firstChild);
				var my_xml1:XML = new XML(xString1);
				var my_node1:XMLNode = my_xml1.childNodes[0];
				var titleString = my_node1.toString().toUpperCase();
				//
				var imageString = xmlRoot.childNodes[m].childNodes[i].childNodes[2].firstChild;
				var linkString = xmlRoot.childNodes[m].childNodes[i].childNodes[3].firstChild;
				arrItem.push(new Array(titleString, descString, imageString, linkString));
			}
		}
		gotoAndStop("start");
	} else {
		trace(xmlFile+" not loaded!");
	}
}
xmlData = new XML();
xmlData.ignoreWhite = true;
xmlData.onLoad = loadXML;
xmlFile = "slideShow.xml";
xmlData.load(xmlFile);

frame4
codice:
stop();
function setLink() {
	for (i=0; i<4; i++) {
		this.container["btn"+i].gotoAndStop("off");
		this.container["btn"+i].enabled = true;
	}
	this.container["btn"+p].gotoAndStop("on");
	timer.timeBar.xSlideTo(-497, 1, "easeInOutQuint", 0, function () {
		if (playStat == "yes") {
			callTime();
		}
		mainWindow.playPause.enabled = true;
	});
	linkBtn.onRelease = function() {
		getURL(arrLink[p-1], "_self");
	};
	mainWindow.mainText.gotoAndPlay(1);
}
function nextPic() {
	if (p<items) {
		_global.p++;
		xVar = mainWindow.content._x;
		mainWindow.content.xSlideTo(xVar-722, 1, "easeInOutQuint");
	} else {
		
		mainWindow.content.xSlideTo(0, 1, "easeInOutQuint", 0, function () {
			_global.p = 1;
			changeChannel();
			var checker:Number = Number(_root.arrMenu.length*4)-4;
			if (gg == checker) {
				_global.gg = 0;
			} else {
				_global.gg += 4;
			}
			
			
		});
	}
	setLink();
}


function changePic() {
	xVar = mainWindow.content._x;
	goto = 722-Number(p*722);
	timer.timeBar.stopTween("_x");
	mainWindow.content.xSlideTo(goto, 1, "easeInOutQuint");
	setLink();
}
function callTime() {
	timer.timeBar.xSlideTo(0, _root.slideTime, "linear", 0, function () {
		mainWindow.playPause.enabled = false;
		_root.nextPic();
	});
}
//
function createButtons() {
	for (i=0; i<items; i++) {  
		mc = container.attachMovie("itemBtn", "btn"+(i+1), i);
		mc.headline = arrItem[Number(_global.gg+i)][0];
		mc._y = i*58;
		mc.id = i+1;
	}
	changePic();
}
//
function changeChannel() {
	for (m=0; m<_root.arrMenu.length; m++) {
		var id = m*4;
		_root["menuBtn"+id].gotoAndStop("off");
		_root["menuBtn"+id].enabled = true;
	}
	_root["menuBtn"+gg].gotoAndStop("on");
	_root["menuBtn"+gg].enabled = false;
	_root["menuBtn"+gg].swapDepths(this.getNextHighestDepth());
	createButtons();
    preloadImages();
}
function createMenus() {
	var fontButton:TextFormat = new TextFormat();
	fontButton.font="skyfont", fontButton.size=14, fontButton.color=0x666666, fontButton.leading=-4;
	//
	var xPos:Number = 1;
	for (i=0; i<arrMenu.length; i++) {
		mc = attachMovie("menuBtn", "menuBtn"+i*4, this.getNextHighestDepth(), {_x:xPos, _y:1});
		mc.id = i;
		mc.buttonNo = i*4;
		var findLength:Object = fontButton.getTextExtent(arrMenu[i]);
		var titleLength = findLength.textFieldWidth+2;
		xPos += titleLength+15;
	}
	changeChannel();
}
//
function preloadImages() {
	timer.timeBar.stopTween("_x");
	_global.howmany = 0;
	var xPos:Number = 0;
	//
	for (i=0; i<items; i++) {
		this.container["btn"+i].enabled = false;
		_root.mainWindow.content["cont"+i].removeMovieClip();
		mc = _root.mainWindow.content.attachMovie("cont", "cont"+i, _root.mainWindow.content.getNextHighestDepth(), {_x:xPos, _y:0});
		mc.photo = _root.arrItem[_global.gg+i][2];
		xPos += 722;
	}
	this.onEnterFrame = function() {
		if (howmany == items) {
			setLink();
			this.onEnterFrame = null;
		}
	};
}
createMenus();


helpppppppppppppppppppppp