I was able to get the exact same issue. I will try with upstream 3.0 firefox but i think its the site that your using. You are right though firefox should beable to change back to normal size (full screen)
** Changed in: firefox (Ubuntu) Importance: Undecided => Low Assignee: (unassigned) => Mozilla Bugs Status: Unconfirmed => Needs Info -- Window stay shrinked when using back button from shrinked page https://launchpad.net/bugs/93367 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs