My ubuntu 13.10 goes on standby when I waking up from hibernate. It shows my desktop (or whatever windows were open when it hibernated) when I turn it on, and then goes on standby, and then when I do any action it asks me for password to log in. There doesn't seem to be any setting that would do this? A bug maybe? I upgraded from 13.04 to 13.10 as this problem started after upgrade.
I had the same issue on a laptop with Ubuntu 14.04.
A few seconds after waking up from hibernation, it complained about weak battery and went on standby.
It looks like it has been fixed since I installed the "laptop-mode-tools" package.
Hope this helps