I'm using version 2.0b2.120226 freshly downloaded from the repository.
I've checked & double-checked my selectors, got the pagination working (that was a chore in of itself). And still, no luck.
I've built a custom child theme based on a premium theme that my client purchased, so I can change the selectors to whatever I need them to be. Even still, it's not loading the new posts at the bottom.
The staging site is here: http://hypevault.taupecat.com/
My selector settings are:
Content Selector: #portfolio-list
Posts Selector: #portfolio-list .tile
Navigation Selector: #pagination
Next Page Selector: #pagination a.next