Have tried to use previous solutions to hibernate or suspend but system will not boot with modified
xorg.conf. Using Oneric with NVIDIA ti4200 graphics card and NVIDIA drivers.
Fixed it eventually by running nvidia config from sudo. The xorg.confg file isn't properly configured when the drivers are automatically installed. Once nvidia control panel has updated the xorg.config the usual work around here works : https://help.ubuntu.com/community/BinaryDriverHowto/Nvidia