Amapy API se nezobrazují ve IE 8

.......... // v head:
<script type="text/javascript" src="http://amapy.centrum.cz/api/api.php5?guid=muj_key"></script>
<script type="text/javascript"> 
var Page = {
    load: function() {
        var mainMap = new AMap("mainMap");
        var mujstred = new AGeoPoint('50°13\'39.135"N; 12°51\'59.223"E');
        mainMap.loadMaps(mujstred, 100000); 
        mainMap.addMapPart(new ASmallMapControl(), new APosition(ACorner.LEFT_TOP, new ASize(10, 10))); 
        mainMap.addMapPart(new AMapTypeControl()); 
        mainMap.addMapPart(new AMapLayerControl([A_TOURISTIC_MAP,A_CYCLE_MAP])); 

var PIcon_1 = new AIcon({
    fastRollover    : false,
    fixPng          : false,
    imageSrc        : 'images/okec/208_ico.jpg',
    imageSize       : new ASize(26, 26),
    shadowSrc       : null,
    iconOffset      : new APoint(13, 13)
});

        var pozice1 = new AGeoPoint('50°13\'15.484"N; 12°52\'54.129"E');
        var marker1 = new AMarker(pozice1,{clickable:true, icon: PIcon_1, title:"Karlovarské městské divadlo, o.p.s."});
        mainMap.addOverlay(marker1);
        marker1.addEvent('onClick', function() { marker1.showBubble("<img src='../images/mini_logo.gif' align='left'><strong>Karlovarské městské divadlo, o.p.s.</strong><br style='clear:both;'>Kliknutím na ikonku maximalizace bubliny <img src='../images/ico_maximalizace.gif'> zobrazíte podrobnosti.", {footerContent: "<div class='amapafootercontent'>GPS: " + marker1.getGeoPoint().toDisplayGPS() + "</div>", 'maxSize' : new ASize(550, 470), 'maxUrl' : 'detail.php?id=23'}); });

    }
}
window.addEvent('domready', Page.load.bind(Page));
</script>

........................... // v body

<div id="mainMap" style="width: 700px; height: 500px; ">
  <p><img src="../images/amapa_loading.gif">
  <br><br>Čekejte prosím, mapa se načítá ...</p>
</div>