I've recently upgraded to 13.10 and I can't find the option to hibernate. My computer doesn't play ball when I suspend it (screen doesn't reactivate upon lifting the lid) so in 13.04 I always used hibernate when lid closes. That option has now disappeared. When I go to power options the option to hibernate is not listed under "Close lid" actions. The only options are suspend and do nothing. I had this same problem with 13.04 but did the following to fix it:
Altered the file
/etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla to say
[Re-enable hibernate by default]
I've tried this again after the update and it doesn't appear to be solving the problem.