I just tried again, and it passed me rbd_isapi.dll.
I'm using Mozilla 1.1, with preferences set to alert me if a site attempts to force a download. MSIE users would probably never get a warning, and it would just be installed, whatever it is.
The relevant part of the source is:
<!----------begin banner stub--------->
<iframe NORESIZE="NORESIZE" FRAMEBORDER="0" WIDTH=468 HEIGHT=60 MARGINWIDTH="0" MARGINHEIGHT="0" SCROLLING="NO" SRC="http://demo-voip.rodopi.com/rbd/rbd_isapi.dll?DistID=55">
</iframe>
<ILAYER WIDTH=468 HEIGHT=60 >
<LAYER SRC="http://demo-voip.rodopi.com/rbd/rbd_isapi.dll?DistID=55">
</LAYER>
</ILAYER>
<!----------end banner stub--------->
I'm guessing that it's some sort of ad snooper.
<add>
On second thoughts, maybe it's something to do with the payment system. Either way, I refuse to accept any downloads from any site, and I would also refuse to list such a site. But that's my own policy, it is not the standard policy of dmoz.org.
</add>