As Custard7A indicated, your images link to unavailable images. But i think the problem you're finding is that your links don't really connect to the <td> tag as the images are just the background.
i think what you can do to allow for your image to show as a link is to change your <td> by removing the background style and adding in an <img> tag and if you want the entire <td> to act as a link you can add the style="display:block" and you can add in the margin to adjust where you want your image to show up in the <td> element.
Here is an example:
<td width="61" height="34"><a href="http://www.inflatableboats.net"><img src='smiley.gif' style="display:block; margin-left:10px;"/></a>
just change the src of your <img> to "http://farm6.staticflickr.com/5546/9326490245_3d60f2d0d9_b.jpg" once you get this fixed
hope this helps