You need to put the
vertical-align: bottom;
on the image, not the cell.
While you're at it, you should move the height and width attributes to CSS also:
.tabletddown_image {
width: 100%;
height: 100px;
vertical-align: bottom;
}
Here's a jsFiddle to demonstrate:
http://jsfiddle.net/qdmX2/[
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