Maybe this isn't supported or otherwise overridden by the Firefox version that you use.

Download a new copy of the Firefox application from the Mozilla server and save the disk image file to the desktop

• Firefox 37.0.1: https://www.mozilla.org/en-US/firefox/all/

• Trash the current Firefox application (open the Applications folder in the Finder and drag the Firefox application to the Trash) to do a clean (re)install
• Install the new version that you have downloaded
• https://support.mozilla.org/kb/Installing+Firefox+on+Mac

Your personal data is stored elsewhere in the Firefox profile folder, so you won't lose your bookmarks and other personal data when you uninstall and (re)install or update Firefox.

• http://kb.mozillazine.org/Profile_folder_-_Firefox

I did what you suggested and got the same result. I re-checked the boolean and it was set to "False"

Any other ideas and/or folks I can check in with about this?

Thanks for your input, Russ

This is still a Boolean pref?

Hello Russ, cor-el

maybe it is stupid question... but the preference you mention is browser.search.showOneOffButtons (with out the dot [.] between show and One), did you create the browser.search.show.OneOffButtons (with the dot) ?

thanks

I didn't create the preference - I just clicked on the one listed on the Firefox "about:config" page