Tuning keyboard in Xubuntu (continued...)

In the previous post I've described a way to make Insert and Delete keys located on numeric keypad to act as plain Insert and Delete. Unfortutately, some programs have problems with arrow keys in combination with Shift key. Since I'm never use numpad for typing numbers, it is better (for me) to use the following ~/.Xmodmap file:

keycode 79 = Home
keycode 80 = Up
keycode 81 = Prior
keycode 83 = Left
keycode 84 = Begin
keycode 85 = Right
keycode 87 = End
keycode 88 = Down
keycode 89 = Next
keycode 90 = Insert
keycode 91 = Delete

It makes these keys indistinguishable from gray ones and makes them independent from NumLock.key state.