This code fails in IE8, but works on FF, Opera, Safari, Chrome, IE7 and IE8 in IE7 mode

var opacity = 0.4;

var myImageType = function(url, opacity) {
 var tileLayer = new google.maps.ImageMapType({
  getTileUrl: function(point, zoom) {
    return url;
  },
  tileSize: new google.maps.Size(256, 256),
  opacity: parseFloat(opacity),
  isPng: true
 });
 return tileLayer;
};

looking around, the only code I have seen working so far is to do styling depending on the engine:

if ( typeof(obj.style.filter)       == 'string' ) {obj.style.filter       = 'alpha(opacity:'+ (this.opacity) * 100 + ')'; }
        if ( typeof(obj.style.KHTMLOpacity) == 'string' ) {obj.style.KHTMLOpacity = this.opacity; }
        if ( typeof(obj.style.MozOpacity)   == 'string' ) {obj.style.MozOpacity   = this.opacity; }
        if ( typeof(obj.style.opacity)      == 'string' ) {obj.style.opacity      = this.opacity; }

but it doesn't use ImageMapType, instead it relies on creating an Img element where opacity is applied.

any fix possible?