The Autocomplete drop-down shows the page title as well as the URL. This is useful for sites where the URL isn't very informative (i.e., paths contain just numbers or codes). There probably is a way to show only the URL, but I can't recall reading about one. Maybe a style rule or add-on.

Thank you. I tried changing autofill in about:config from true to false, but it didn't change anything in my dropdown menu. Strangely it was working like i want until about a week ago when Norton went into my PC to remove a tricky malware!

Found my solution messing with "location bar" in google. Add on "old location bar" ver 2.1.6. Case closed!

And in case anyone wants the link: https://addons.mozilla.org/en-us/firefox/addon/old-location-bar/