Time zone map can't be navigated with the keyboard

Binary package hint: ubiquity

Ubuntu Jaunty alpha 6

1. In the installer, advance to the "Where are you?" step.
2. Click on Japan to select Tokyo.
3. Press the Left key.
4. Press the Right key.
5. Press the Up key.
6. Press the Down key.

What should happen:
3. The +8 time zone should become highlighted, and Shanghai should be selected.
4. The +9 time zone should become highlighted, and Tokyo should be selected.
5. The +9 time zone should remain highlighted, and Seoul should be selected.
6. The +9 time zone should remain highlighted, and Tokyo should be selected.

What actually happens: Nothing.

To implement this:
* The Left or Right key should highlight the next western or eastern time zone respectively, and select the city in that time zone that is closest in latitude to (A) the point that was last clicked or (B) the city that was last chosen from the menu, whichever happened later. (Using the latitude of A or B, rather than the latitude of the currently selected city, avoids any situation where Left followed by Right (or vice versa) does not return you to the city you came from.)
* The Up or Down key should select the next northern or southern city respectively in the highlighted time zone.

Not to be confused with bug 242173, which is about navigating the menus with the keyboard.