can't start gadget in sandbox

[elpenultimo]

Hi,
I'm trying the Chess game gadget (in sandbox) , but, when I send the
invitation to play, my friend got this:

elpenultimo has invited you to use http://code.google.com/apis/talk/examples/chess.xml.<br><a
id="accept_0.11365983852722072" href="javascript:void(0)">Accept</a>,
<a id="decline_0.11365983852722072" href="javascript:void(0)">Decline</
a> or <a target=_blank href="http://code.google.com/apis/talk/
gadgets_realtime.html">Help</a>

(As you can see, we only see the code, but not the link to start the
application)
How can I solve this? We're using Firefox 3.6

Thanks!!