#6 Older versions.
Backup the bookmarks Ctrl + Shift + B
Import and Backup> Backup and save to your desktop.
If Firefox did not import then you can manually by clicking on Restore> Choose File and browse to the desktop file.
Uninstall the new version and install the older version.
All your extensions may or may not show up.
http://mozilla_firefox.en.downloadastro.com/old_versions/
So far running great