They are showing up fine on my computer.
I would sort out your background tho, (purple) it doesn't fill the wholce page.
Use the following code in your style sheet (css) to reset the margins and padding, this solves the issue.
/* Resetting the borders, margins and padding on all items, then setting up font sizes ***********************/
* { margin: 0; padding: 0; text-decoration: none; font-size: 100%; outline: none; }
code, kbd, samp, pre, tt, var, textarea, input, select, isindex { font: inherit; font-size: 1em; font-family:inherit; }
body, div, h1, h2, h3, h4, p, dl, dt, dd, img, form, fieldset, blockquote { margin: 0px; padding: 0px; border: 0px; }
Also I would lose some of the space at ther bottom of the page unless you are planning to add text or something there. It is annoying having to scroll down to find that there is nothing there.