IE and external javascript

I’m trying to display a petition from ThePetitionSite.com in the sidebar on my site at http://mahonewoodsandfield.net/. It is working in Firefox and Opera, but does not work in IE6 or IE7. ThePetitionSite gives the following code to use (this is a new feature for them, and still in beta), which I have added to the sidebar.php file:

<div id=”peSiteTargetDiv339508803″>Petition powered by ThePetitionSite.com</div>
<script src=”http://www.thepetitionsite.com/js/widget.js?petitionID=339508803″></script&gt;

All I get is the “Petition powered by…” text, not the box which contains a textfield, a button and a list of recent signatures as you see in Firefox.

Can anyone help? I noted some similar topics here about adding Flash to WP, where it didn’t show up in IE without an OBJECT tag; is this similar, and how would I implement it?