modifying my xorg.conf with my old informations from hardy solve the problem :
Section "InputDevice" # generated from default Identifier "Keyboard0" Driver "kbd" Option "CoreKeyboard" Option "XkbRules" "xorg" Option "XkbModel" "pc105" Option "XkbLayout" "fr" Option "XkbVariant" "oss" EndSection
modifying my xorg.conf with my old informations from hardy solve the problem :
Section "InputDevice"
# generated from default
Identifier "Keyboard0"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "fr"
Option "XkbVariant" "oss"
EndSection