If you recently updated from Firefox 3.6 the behavior is different. Now, unless you type an actual url in the location bar, we do a search for you. In Firefox 3.6 and earlier, we tried to make a guess about what site you were trying to go to and then just send you there automatically. This behavior wasn't predictable - sometime it took you to a website and sometimes it did a search. We changed it beginning in Firefox 4 to always to a search. You can learn more about how this works and all kinds of cool tricks to speed up your browsing in this article: Address bar autocomplete suggestions in Firefox

I have not updated my Firefox, and I DO type in the url. Even when I am at a particular website, the top bar where you are supposed to see the url just has what I typed in, or it's blank. For instance, I type in - https://login.yahoo.com/config/mail?.intl=us and instead of taking me directly to the site that I type in, it brings up search results. When I click on the result that corresponds with the link I "searched for", the navigation bar stays the same. It never changes, even when I click on a new link. I have included a picture of what I am seeing.

Ah! It looks like you've replaced your location bar with the search bar. I recommend resetting things to the default.

Follow the instructions here Customize Firefox controls, buttons and toolbars but instead of customizing, click Restore default set.

Thank You!!! That fixed It! YAY!!!  :)

Would've been nice to leave us with the option. The search is unnecessary if I know where I'm going, and now I have to type in an entire url when I didn't before. I didn't find it "unpredictable" at all. So one feature is taken away and replaced with a second way to do something I was already able to do anyway.