Prova sätta höjden på drop-down menyn till 0, så syns den aldrig.
Citat:
For those who do not want to dive under the hood, setting the drop-down height to zero rows usually will suppress it entirely:
(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.
(2) In the search box in the page, type or paste URLB and pause while the list is filtered
(3) Double-click the browser.urlbar.maxRichResults preference to display an editing field, and change the value to 0 then press Enter or click the blue check mark button to save the change.
