Comment 2 for bug 954668

I'm investigating this on my HP Mini netbook.
The fix in /etc/polkit is already present on my precise build, still no hibernate option.

One apparent gap in the build is a kernel command line argument to indicate where to find the hibernate image.

I've got this now; the 'resume' argument, but I can't initiate hibernate (via the GUI) so can't test it -

$ cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-3.2.0-20-generic-pae root=/dev/mapper/valiantvg-lv00sys00 ro resume=/dev/sda2 quiet splash vt.handoff=7

based on docs here, this is required

https://wiki.archlinux.org/index.php/Pm-utils#Hibernation_.28suspend2disk.29

added it by amending

/etc/default/grub as follows ..

GRUB_CMDLINE_LINUX_DEFAULT="resume=/dev/sda2 quiet splash"

and then running sudo update-grub