Greasemonkey and Firefox 10. Autopager will randomly stop working requiring manual change.

 

For anyone still looking for a working autopager, Fanfiction Tools by ewino has one and some other nifty features besides, like autoclosing the top menus, autopaging search pages, parsing update dates to tell you the rate of updates, and coloring update dates according to age.

EDIT: I'm assuming the autopager referenced in this thread is slightly broken judging from the replies over the last page or so. If not then the script I mentioned still has some other good features.