infinite scroll is looping

Hi, my-your infinite scroll plugin works but at the end of the internet it loops at the “first page”. What have I done?

my site: http://www.migio.com
Brunelleschi theme; selectors ->
#main
#nav-below
.nav-previous a:first
.post
Brunelleschi theme; selectors ->

Thanks.

http://wordpress.org/extend/plugins/infinite-scroll/