This shouldn't happen. Changes made manually on the about:newtab page are stored in prefs that you can find on the about:config page. *browser.newtabpage.pinned stores websites that you have pinned to a tile. *browser.newtabpage.blocked stores websites that you have removed by clicking the X button in a tile. You can check for problems with preferences. Delete possible user.js and numbered prefs-##.js files and rename/remove the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in current Firefox releases. *http://kb.mozillazine.org/Preferences_not_saved *http://kb.mozillazine.org/Resetting_preferences You can use this button to go to the current Firefox profile folder: *Help -> Troubleshooting Information -> Profile Directory:<br>Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder *http://kb.mozillazine.org/Profile_folder_-_Firefox