gnome-power-manager and hibernate-disk

[Gerard Robin]

Hello,
I use sid (kernel 2.6.22-1-amd64) on my laptop and after apt-get update, upgrade 
gnome-power-manager (2.20.0-1+b1) doesn't work, however the command hibernate-disk works fine.
What am I missing with gnome-power-manager ? 

tia.
--
Gérard