Before I got the phone I had read on net that there were problems with alarm not going off sometimes and many times it was related to task killers or clock not updating. I didnt believe them at first but when I got the phone out of 3 days the alarm didnt go off for 2 days even when the clock app wasnt killed making it highly unreliable. Then after that it worked well for 10-15 days slowly building the confidence and now once again this morning it refused to go off!! Though I didnt have any important work scheduled this morning but in case of any prior commitments it is highly unreliable to trust the alarm. I wonder what stops it sometimes since surely its not the task killer. This time I guess my battery was below 20%. Since some default android apps dont work on low battery (Camera, Video player etc) maybe the alarm also didnt work. But when I woke up after some time the screen was ON, the clock app was using fair amount of CPU usage and had drained quite a good amount of battery. SUSPICIOUS BEHAVIOUR!