One issue is that the Facebook iframe width is set to 450px, causing its parent element to stretch and pushing the buttons below the text. You can solve this problem by setting a fixed width for the wrappers as shown below:
#social li {
display: inline-block;
text-decoration: none;
padding: 0 0 0 33px;
float: left;
max-width: 80px;
overflow: hidden;
}
By adding the last two lines, the layout should now display correctly.
A more effective solution would be to avoid using iframes altogether and instead create your own buttons using the respective APIs provided by Facebook (or Twitter and G+). This approach allows for complete styling customization and may even enhance page loading speed. However, it might be considered overly complex...
You can view the updated code snippet here: http://jsfiddle.net/eYQWE/2/