It seems that the problem is not only in IE 8 but in all browsers that are not on my machine.
When I debug I get a warning:
warning: unable to bind to property 'value' on class 'Object' (class is not an IEventDispatcher)
So I am guessing the problem is that the legend cannot find the binding expressions myURL.selectedItem.value that is inside the dynamic layer's url property, which changes according to the selected item in the combobox called my URL. It seems that the problem might be that I need to bind that variable, however I might have to use an Object Proxy . I tried to do that but it did not work. Here is my code snippet that is not working:
[Bindable] public var myURLvalue:ObjectProxy = new ObjectProxy(measures);
[Bindable] public var myURLObject:Object = myURL.selectedItem;
[Bindable] public var value:String = myURLObject.value
Any ideas?