I am using two java applets in my web page (let's call them '''XMLPlugin''' and '''DSigner'''). I create Java object by calling XMLPlugin applet's method "createObject(<params>)": '''var myObj = XMLPlugin.createObject(<params>);''' Method createObject returns object of type '''<my_type>'''. I want to send myObj to the other applet DSigner: '''DSigner.addObject(myObj);''' I get following exception in Java:uncaught exception: '''java.lang.ClassCastException: sun.plugin2.main.client.MessagePassingJSObject''' cannot be cast to <my_type>. Problem is, I am getting object of type MessagePassingJSObject instead of <my_type> returned by createObject() method. Strange is that Firebug shows correct type <my_type> for variable myObj before entering the method DSigner.addObject(myObj). I am also getting correct objects using other browsers (Internet explorer, Chrome). Thank you, any help would be really appreciated.