If you have an index page that has galleries on multiple pages, and then you select to sort by most recently updated (i.e. ?sort=recent), it magically thinks there is only one page. For example, both Smoove and Framed don't hold all of my galleries on one page, and the bug appears when using both styles.
I played a bit, and it looks like the problem is that it thinks that $.sorted_pages.all_subitems_displayed is true even when it's not. This only happens with ?sort=recent though.
Let me know if you need any more info about this. :)