I've added infinite scroll support of the Jetpack plugin to my own theme with:
add_theme_support( 'infinite-scroll', array( 'container' => 'content', 'footer' => false, 'render' => 'vividflow_infscroll_render', 'wrapper' => false, 'posts_per_page' => 12 ) );
vividflow_infscroll_render just loads The Loop.
However, I'm experiencing some trouble with the infinite scroll: new posts are loaded multiple times, so that I get double posts on the archive page. My archive page looks like this:
I think new posts are loaded several times because I have several posts on the bottom line: 3. When I place all the post summaries beneath each other, there is no problem.
How can I resolve this issue?