In the original, the CSS for #navigation has float:left. If I do that in the new CSS, all the buttons stack up next to the logo on top of each other. Adding the margin-top value to the new CSS just moves the buttons AND logo down.
It is strange. Looking at the div in Firebug something is very strange.
When hovering over the div in the left pane, it usually highlights the div in light blue in the top pane (the browser window). But it highlights it in yellow and, even if I set the width to 725px, it shows it the full width of the container.