[xmonad] Problem with accessibility

[Maurí­cio]

Hi,

I use mouse keyboard control (i.e., I press Alt-Shift-NumLock and then I 
can use the numeric pad to control the mouse). However, when using 
xmonad, I loose that control at random times. I've confirmed that this 
seems to be a problem with xmonad, since in metacity it works well.

This is my xmonad.hs:

----------------
import XMonad
import XMonad.Layout.Grid

main = xmonad $ defaultConfig {borderWidth=11, modMask=mod4Mask,
     normalBorderColor="#00ff00", focusFollowsMouse=False,
     layoutHook =((Tall 0 (1/100) (1/2)) ||| (Tall 1 (1/100)
     (9/10)))}
----------------

What do you think may be the reason for that?

Thanks,
Maurício