Make sure you check to see if the links it provides are not from your bookmarks, because the latest release of FireFox has something called 'Awesome Bar", which basically searches through your bookmarks and offers the closest to your query. (that last word is probably spelled wrong. I need sleep)
I do believe, however, you can stop this by changing the following values in about:config :::
QUOTE
places.frecency.unvisitedBookmarkBonus - integer - 0
places.frecency.unvisitedTypedBonus - integer - 0
If that doesn't work, please inform me, and I'll figure out what I did to discontinue it.