Comment 30 for bug 1283938

I have the same problem on old Dell 1525 laptop with an update to Ubuntu 14.04 final release from 13.10.

 I seem to have temporarily fixed the problem by doing the following:

Go to Security & Privacy - Un-check the ticked boxes under
Require my password when
'Waking from Suspend'
'Returning from Blank Screen'
i.e. no passwords needed after suspend

This seems to be working so far and the machine wakes up okay after I shut the laptop lid and the machine has entered suspend mode. Whether it's a full fix I don't know, but it is working for now.