Grid Layout problem

Some times the Home Page loads the grid layout and some times it load full width items (on the section last post, most times it loads full width)

I see on the code that when it loads the grid it has the “span4” and “tc-grid” and when it loads the full items it has “row-fluid”

I want the Grid system, I’ve set up on the Appearance settings, but mostly times it loads the full width items

Can you Help me ?

The temporary url that i work is: http://bienalouruguayo.com/guia-rocha/

Thanks in advance