1) This is for when you highlight a word, right-click on it for the drop-down menu, and choose a search engine to open results in a new page in Firefox.
2) I used to have it set to duckduckgo.
3) Then I decided to try adding Norton toolbar at the top of the FF browser.
4) Changed my mind, unchecked Norton toolbar.
5) Discovered Norton hijacked ^1) above in this post. >.<
6) I even went into FF Add-ons and disabled Norton Toolbar, but still can't get duckduckgo back as my preferred search engine.