[ixtab]

No... that doesn't make sense. All the K4 firmwares that I have here (the earliest one being 4.0.0) all come with kindlet-1.3.jar.

And the 1.2 one (from K3 3.4.0) reads:

// Decompiled by Jad v1.5.8e. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://www.geocities.com/kpdus/jad.html
// Decompiler options: packimports(3) 
// Source File Name:   pob

package com.amazon.kindle.kindlet.event;


public final class KindleKeyCodes
{

    private KindleKeyCodes()
    {
    }

    public static final int VK_FIVE_WAY_SELECT = 61451;
    public static final int VK_FIVE_WAY_LEFT = 37;
    public static final int VK_FIVE_WAY_RIGHT = 39;
    public static final int VK_FIVE_WAY_UP = 33;
    public static final int VK_FIVE_WAY_DOWN = 34;
    public static final int VK_RIGHT_HAND_SIDE_TURN_PAGE = 61448;
    public static final int VK_LEFT_HAND_SIDE_TURN_PAGE = 61449;
    public static final int VK_TURN_PAGE_BACK = 61450;
    /**
     * @deprecated Field VK_FONT_SIZE is deprecated
     */
    public static final int VK_FONT_SIZE = 61447;
    public static final int VK_TEXT = 61447;
    public static final int VK_SYMBOL = 61443;
    public static final int VK_MENU = 65482;
    public static final int VK_BACK = 61441;
}