designMode="on" for iframe - event handler on radio/checkbox input type not working?

     Hello everyone;
I'm running into an issue here and can't find out how to fix it.

I have an iframe inside a page, this iframe has the designMode property 
set to "on".
I assign event handlers to the contentWindow using such script:
document.getElementById("ElementId").contentWindow.addEventListener("click", 
myEventHandler, true);

In the myEventHandler function I do:
var ClickedElement =  mEvent.target;
alert(ClickedElement.nodeName);

This work for many elements that are inside my iframe page (img, span, 
div, h1, etc) but fails for 2 tags (I haven't encounter the problem with 
other element but who knows) which are the radio and checkbox input types.
I tried to set a onfocus, onclick, onselect in the input tag itself but 
the event just isn't being triggered at all but I believe this is normal 
behavior in designMode.

I also added event handler for focus, select but with no success and 
also by assigning event handlers to the object I insert in the iframe like:
oObj = createElement("input");
..
oObj.onclick=ClickFunRef;


Sorry if this is a wrong place to ask and thanks for ideas you could have.

Scal