I have an ubuntu 12.04 laptop and it comes out of hibernate or standby randomly.
For example, yesterday I selected hibernate, closed the lid and put it in my computer bag. 24 hours later, it is still closed, in the bag, not doing anything. (I check it was there, not running, cold. Six hours later it has come out of hibernation, has 3% battery left and has overheated to the point I can't recharge the battery. This has happened without opening the lid.
This has happened a few times before, where I put it on standby or hibernate, close the lid and I come to use it hours later and find it is running again even though the lid is still closed.
The only way to prevent this at the moment is to do a full shutdown. Is there a way to prevent it coming out of hibernate or stand by spuriously. Note: even if it does come out of hibernate it is set to hibernate after 30 minutes idle, which it doesn't do, it just runs until the battery is flat.