调用google广告的问题

我想把google广告代码插入到第3个item后面，ie都正常，FF却一直加载中。不知道怎么解决，希望高人指点。多谢了！
代码如下
头部js。
<script language="javascript" src="/js/jquery-1.3.1.js"></script>
<script type="text/javascript">
$(document).ready(function(){
        adstr=$('.googlead');
        $('.item:eq(2)').after(adstr);
})
</script>

body中内容。
<div class=".item">1</div>
<div class=".item">2</div>
<div class=".item">3</div>
<div class=".item">4</div>

<div class='googlead'>
<script type="text/javascript"><!--
                    google_ad_client = "pub-7334090379691568";
                    /* 728x90, 创建于 08-8-26 */
                    google_ad_slot = "2863314081";
                    google_ad_width = 728;
                    google_ad_height = 90;
                    //-->
                    </script>
                    <script type="text/javascript"
                    src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
                    </script>
</div>

帮忙顶哈