Shawn King's post | Latest updates on Sulia
"Why will Apple's Do Not Disturb bug fix itself next week?" I have no clue but Ars Technica seems to know.
Reading Jacqui Cheng's explanation makes perfect sense to me...but it doesn't mean I understand a word of it.
It does seem to line up with what many of us guessed - it's a coding issue that Apple should have known was going to happen but, now that it has, it will fix itself faster than Apple can push code out to remedy the situation. http://arstechnica.com/apple/2013/01/ask-ars-why-will-apples-do-not-disturb-bug-fix-itself-next-week/