Flash ad in front of drop-down menu

[dvsDave]

My website, http://www.controlbooth.com/forums/index.php?styleid=15 has a banner ad running below the navbar.

Code for banner ad:
<center><div style="position: relative; z-index: 0;">
<!--/* OpenX Javascript Tag v2.7.25-beta */-->

<script type='text/javascript' style="position:relative; z-index: 0;"><!--//<![CDATA[
var m3_u = (location.protocol=='https:'?'https://d1.openx.org/ajs.php':'http://d1.openx.org/ajs.php');
var m3_r = Math.floor(Math.random()*99999999999);
if (!document.MAX_used) document.MAX_used = ',';
document.write ("<scr"+"ipt type='text/javascript' src='"+m3_u);
document.write ("?zoneid=10575");
document.write ('&amp;cb=' + m3_r);
if (document.MAX_used != ',') document.write ("&amp;exclude=" + document.MAX_used);
document.write (document.charset ? '&amp;charset='+document.charset : (document.characterSet ? '&amp;charset='+document.characterSet : ''));
document.write ("&amp;loc=" + escape(window.location));
if (document.referrer) document.write ("&amp;referer=" + escape(document.referrer));
if (document.context) document.write ("&context=" + escape(document.context));
if (document.mmm_fo) document.write ("&amp;mmm_fo=1");
document.write ("'><\/scr"+"ipt>");
//]]>--></script>

I set the z-index to 0 on the div surrounding the banner ad. When a flash ad is run, and you click the "Quick Links" dropdown, the menu goes under the flash banner ad (does not happen with a jpg or gif banner ad)

any ideas?