I still use this on firefox v6 portable (I think you have to edit package to override version number check) but not all sites work with it. I am also trying on another PC with the "Re-Pagination by Nils Maier" and firefox v25 that too works with some sites. Hope that helps people. The mentioned addon is listed in my collection if your search wont find it.
EXAMPLES using "next page" link on pages at dana-juno.tumblr.com (just dog pics): -- RE-Pagination by fremea - will re-page ok on that site ffx v6.x -- Re-Pagination by Nils Maier - will re-page works ok
using "older entries" link on pages at any wordpress based site: -- RE-Pagination by fremea - will re-page works fine on firefoxx v6.x -- Re-Pagination by Nils Maier - will re-page on firefox v25.
Those are the main sites see I use it for. Your mileage may vary depending on site visited it just depends how the page link is implemented.