Strange problem with my Verizon iPhone 4. I got a new app called Sleep Cycle, and I've been using it for the past few weeks. I charge my phone to 100% before bed, then unplug it so I can use the app overnight to track my sleep cycles and wake me up. It has been draining about 20% per night. The last two nights I woke up and my phone was powered off. The battery drained completely. Even worse than that, if I recharge it in the morning the battery will continue to draining very quickly through the day. Closing apps and rebooting it don't help, but if I do a hard reset it does fix the problem. Thoughts? I'm running iOS 5.1.1, not jailbroken.