This same bug is probably what broke iPhones coming out of Do Not Disturb mode in January 2013. http://arstechnica.com/apple/2013/01/ask-ars-why-will-apples-do-

This same bug is probably what broke iPhones coming out of Do Not Disturb mode in January 2013. http://arstechnica.com/apple/2013/01/ask-ars-why-will-apples-do-not-disturb-bug-fix-itself-next-week/ http://arstechnica.com/apple/2013/01/ask-ars-why-will-apples...