Size is wrong on page load

When the page loads, the tiles do not fill up their area, and as they are not centered the design is off.
Upon resizing the window, the tiles catch up and grow into their right size fitting perfectly.

http://wip.andreasekstrom.se/

Is there a way to get around this so the viewer don’t have resize the windowtoget the right design?? and if so, how?

http://wordpress.org/extend/plugins/wp-tiles/