I personally don't use suspend or hibernate as I don't like screens blanking on me , I would simply log out if leaving my keyboard for any length of time if I were in a strange place, at home I just switch off the monitor!.
As @rev pointed out, there is a bug and this has been the case for a long time now causing problems for many users!.
All I have to offer is the following link which has nothing to do with suspend!:
, I would simply log out if leaving my keyboard for any length of time if I were in a strange place, at home I just switch off the monitor!.