Rated 5 out of 5 stars

for me AutoPager is one of the best Firefox extension.

the same thing that happened to titof_91 has happened to me too but still this extension is one of the best for sure

This review is for a previous version of the add-on (0.6.0.10). 

This feature help users avoid load the same pages again and again. There are a lot of request for this feature, that's why there is such a feature.
You can turn it off by uncheck Tools->AutoPager->Tweaking Session.
Or use the back dropdown to back to the original page.