Gah, I tried Kaloer Clock since it seems to have an entirely separate alarm, and the exact same thing happened. I turn on my screen after the time the alarm is meant to go off, but the time has stopped at 6am so nothing happened =\. This time, when the clock updates itself the alarm actaully did go off, but it was like an hour late and obviously i was already awake, so pretty useless.
Seriously nobody else has had this problem, or noticed their time lagging when coming out of power saving??