Key Codes not working properly on key events

Consider the following code:

``` clojure
(listen! (sel "body") :keypress (fn [evt] (println "Keypress" (:keyCode evt)))) 
```

On Chrome, I see ASCII codes printed out properly for alphanumeric keys, but no event is received and thus nothing is printed for arrow keys.
On Firefox, I see codes printed out properly for arrow keys, but all alphanumeric keys print a keyCode of 0.
