twitter-bootstrap - Popover Bootstrap 左侧位置是否为负？

Question

http://www.sagu.edu/tv/channels/seminars

<div class="popover fade top in" style="top: 750.6000061035156px; left: -125.80000019073486px; display: block;"><div class="arrow"></div><div class="popover-inner"><h3 class="popover-title">Introduction to Life &amp; Thought during the Civil War</h3><div class="popover-content"><p>SAGUTV - ALT TEXT</p></div></div></div>

代码是通过这里生成的另一个 php 生成的：

<div class="thumbnail">
    <a href="{URL}/{ID}" rel="popover" id="{IID}" data-content="{IMAGE_INTRO_ALT}" data-original-title="{TITLE}">
        <img src="{IMAGE_SRC}" title="{TITLE}" class="nspImageWrapper tcenter fnone gkResponsive"></a>
    <span class="center tuck-caption">{TITLE}</span>
</div>

<script>
$(function () {  
    $("#{IID}").popover({placement:'top'});  
});  
</script>

不知道为什么左边的标签在 -130px 处计算；有任何想法吗？