Bug report: Calendar on iOS 5 Notification screen consumes constant CPU and decreases battery life
After upgrading an iPod Touch 3 and 4 to iOS 5 and customizing the notification screen to include the Calendar (synced to an Exchange account), the battery life of both devices seems significantly worse. Removing Calendar from Notifications returns things to normal. I suspect a CPU issue because of the following observed behavior: when the Notification screen is visible, the calendar items are observed to be re-ordering themselves near-constantly (the first item keeps getting added and removed indefinitely) and the smooth scrolling of the stocks notification at the top of the screen is extremely slow and stuttery. Removing Calendar restores the scrolling to normal; adding it back leads to the slow/stutter behavior.
I don't know if this is contributing to the overall battery problems with the iPhone 4S, but it definitely seems to be an issue for upgraded iPod Touches.
I hope this is helpful.
iPod touch, iOS 5