I'm having problems getting the alignment of images on my site correct. The vertical alignment is fine, but horizontally, it's screwed up. Here is the HTML code for the div. 

<div id="gallery">
     <table cellspacing="0">
      <tr height="400px">
       <td align="center">
        <img name="mainimage" src="../images/gallery_back.jpg" />
       </td>
      </tr>
     </table>
</div>

And here's the CSS:

#gallery {
height: 400px;
width: 400px;
position: relative;
bottom: 95px;
left: 89px;
vertical-align: middle;
text-align: center;
}

In IE, it displays fine, but in Firefox, the images get aligned to the left.  Can anyone help me with this?