The Fn keypad on a laptop does not behave properly at first boot

[Damien]

On a laptop with the keypad integrated into the keyboard via a function key and a num lock key to switch from letters to numbers.

(tested by switching to tty1 to see the input)
Pressing the keys corresponding to the keypad position (in my case 1/j, 2/k, 3/l, 4/u, etc) move the cursor around.
Hitting numlock once and the keys register numbers.
Hitting numlock a second time make the keys register letters.
The cursor behaviour is never regained.

I noticed this while trying to enter my password. I don't know if it is specific to greeter or if this behaviour is carried upon the desktop.

I'm using an Eee901 and elementary has the latest updates. I noticed this behaviour since over a week now.