cannot get thickbox to open / tb_show function ignored

Question

I have two links that should open up thickbox's in iframes but only one works (the one with the id of product_photo_zoom_url2). I have the following jquery code that works when this code (in first code box) s removed from the markup. This code loads a picture zoom function. See complete markup below. All that happens when the first zoom image is clicked is the page goes to the top so it seems that the .click bind is being ignored? How do I get this to work?

onload="vZoom.add(this, '/v/vspfiles/photos/70367301P-2.jpg');" /

jquery code...

var titleattr = $("a#product_photo_zoom_url").attr("title"); 
function picurl()
{
tb_show(titleattr, '/PhotoDetails.asp?ShowDESC=N&ProductCode='+ global_URL_Encode_Current_ProductCode + '&TB_iframe=true&height=600&width=520');return false;
} 
$("a#product_photo_zoom_url").click(picurl);
$("a#product_photo_zoom_url2").click(picurl);
$("a#product_photo_zoom_url").attr('href', '#');
$("a#product_photo_zoom_url2").attr('href', '#');

Here is the html code

<a id="product_photo_zoom_url" href="/PhotoGallery.asp?ProductCode=70367301P"
title="70367301P Ignition Box">
<img id="product_photo" src="/v/vspfiles/photos/70367301P-2T.jpg"
border="0" alt="70367301P Ignition Box" onload="vZoom.add(this, '/v/vspfiles/photos/70367301P-2.jpg');" /></a>
<a id="product_photo_zoom_url2" href="/PhotoGallery.asp?ProductCode=70367301P" title="70367301P Ignition Box">
<img src="/v/vspfiles/templates/100/images/buttons/btn_largerphoto.gif" border="0"></a>