As opserty said, forget about using images for a while and work with the code. Put a label in each of your divs (just some text so you can see where things are on the page) like <div id="Side_Bar03">Side bar 03</div>.

Then take out your images from the CSS and just apply background-colors, again so you can see where things are on the page. Then play around with positioning, etc. Once that's done, and only ONCE IT IS DONE, you can replace the background colours with images.