stripScripts(true) problem in FF 3.5

in the Demo MooEditable.html, if we change the load event, as the
following:

  window.addEvent('load', function(){
    var s3 ="<div> adfa</div> <script>$('textarea-1').mooEditable();<\/script>34523";
    s3.stripScripts(true);   // line 1
    //window.eval("$('textarea-1').mooEditable();");   // line2
     });
    </script>

In ie, chrome,opera, safari, the Editor works well,
in firefox, we can see all buttons, but the Editor can not input a
letter, and the Editor has no default value.

line 2 works well in firefox.

I use mootools to catch a page(html page) and need run all
javascripts in the page.