I just checked this out in ff and if you go 'next', it works, but if you click 'prev' and keep going backwards, you'll notice that you will have slides 1, 2, 1, 8, 7, 6, .... So clicking on either button does the adding of additional images, but they are only available after you clicked, hence if you go backwards, you jump to the 2nd image instead of 8. You can also observe this in html view of firebug. Actually this is quite obvious, since the option 'before' runs just before it reacts to your click, so the new images (added with addSlide) are not available until that point!
I have the same problem trying to have my own pager, only 2 imgs within the html, and the rest added via js. On first interaction only the initial 2 can be interacted with... Hope it will be fixed soon! :) Thanks, Suhi
