Try go to about:config, search for browser.urlbar.autocomplete.enabled change its value to false

• about:config

Thanks but that is not the answer. My problem is auto search not auto complete. I like auto complete...hate auto search :-) I did what you suggested but auto search was still on. I noticed there are a lot of entries titled "browser.search" but I was not sure if one of them might stop the automatic Google search. As I mentioned, I already have keyword.enabled set to false but anything I type in the address bar triggers a Google search. Very annoying..

Found the answer! I was using a Firefox add-on called Fastest Search and it was forcing an instant search in the URL bar. Disabled that feature in its options and all is well.