Bug with embedding tumblr in three-column layout (jquery masonry)

[JmEsyou]

I've embeded tumblr into my website, this works fine but when I'm implementing the three-column layout (jquery masonry) it's giving problems. Sometimes it works fine but sometimes when the page is loaded some of the images are shown above each other. Can someone explain this?Here's the page: http://www.yannickluijten.be/waldCode:\[code\]<div id="container" class="container"> <script type="text/javascript" src="http://luijten.tumblr.com/js?num=30"></script></div><script src="http://stackoverflow.com/questions/15624066/js/jquery-1.7.1.min.js"></script><script src="http://stackoverflow.com/questions/15624066/js/jquery.masonry.min.js"></script><script>$(function(){ var $container = $('#container'); $container.masonry({ itemSelector: '.box' });});</script>#container { width: 960px; height: auto; margin: 0 auto; margin-top: 50px; margin-bottom: 20px; clear: both;}.box { margin: 5px; float: left;}.column { width: 310px; height: auto;}\[/code\]