Inline elements don't have a set height and width, they just fill to the content, so if you have nothing in the inline element it never gets large enough to display the background image.
Just set float:left
I'd suggest putting all your floated divs in a container div also set to float:left;
Then if you have any content further down the page, you'll put it in a container with clear:left;
This will ensure that the container of your floated elements maintain its place in the dom and allow you to properly adjust its margins.
Helping to build a bigger box. - Adam Matthews
Last edited by Basscyst; 10-04-2012 at 10:56 PM..