When viewing your source it is easy to determine the cause of your problems: you are using a table layout.

Try not using tables at all for this. anywhere.

Instead, use div tags with class names. Then in your .css file define the class names, and make sure to define the width and height of the div elements.

for multiple columns, you would instead make multiple div tags, with the css defining the width and setting position:relative and float:left. This makes each div act like an image aligned to the left, then will arrange nicely next to one another. To stop this, simply add a <br clear="left" /> tag.

Tables are evil and should only be used to display table data.