I don't think I can see the problem as the content goes below the bottom of my window, so the black just shows on the left.
If you want to keep the black from showing under the footer, you could use a wrap div with the black background and it would then stop below the footer so the white would show below the footer.
Your markup has a wrap div called #everything but the style in the css file is commented out. Try adding the black image to that with no-repeat; instead of the body style.
Also, why use a very large image for a plain black color instead of just a background-color?
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.