I was having the issue of firefox not enabling the back, forward, stop, or refresh buttons no matter what. I had navigated and had valid history, but they refused to show. Apparently firefox uses sqlite for its history or something.
The problem was the file: ~/.mozilla/firefox/blahblah.default/places.sqlite-journal only had root access. Changing this file with a chmod 777 fixed the problem. Now I can properly use firefox in Ubuntu again.