It is always recommended to use the latest release, because earlier releases have publicly disclosed security vulnerabilities. Could you be more specific about the problem you're running into with Firefox 31? Some things that might help: * If you like using the classic menu bar, you can turn that one using any of these: ** right-click a blank area of the tab bar ** right-click the "+" button on the tab bar ** tap the Alt key > View > Toolbars ** "3-bar" menu button > Customize > Show/Hide Toolbars * If you liked using the orange Firefox button, I have a page showing where those commands moved to in the "3-bar" menu: http://www.jeffersonscher.com/res/menu/comp.php * To comprehensively revamp the user interface, you can use this extension: https://addons.mozilla.org/firefox/addon/classicthemerestorer/