When you quickly want to go to a directory by starting to type its name the text you've typed so far is shown in a small textbox in the left bottom of Nautilus.
This textbox has the focus, so you correct mistakes you made or refine the search by adding another character.

However, the way this is done does prevent you from using the arrow keys to navigate the directory, you first have to press ESC or click on the screen to let the search box lose its focus.
It would be much easier if you could just use the arrow keys to select directories right away.

There was already a small discussion downstream; the following suggestions were presented:
* Remove the search box altogether; remember, but hide the search string.
* Do it the Emacs way: only send new characters and backspaces to the search box, all other keyboard input to the folder view.
* Only not send the arrow keys events to the search box, but instead direct them by default to the folder view.

This bug was originally reported by Mika on Launchpad in Ubuntu at <https://launchpad.net/bugs/404042>.