I've found a very unfortunate bug. For no specific reason, my screen goes completely black while running iOS 8 beta 1. It's completely unresponsive, as far as I can tell. Siri works, but I've yet to find a way to get my screen on. Last night, I ended up updating through iTunes (again) in order to bring it back to life. Has anyone else experience the black screen of death while running iOS 8?