Installed beta 4 today and this has happened atleast 4-5 times now. When i go to my notifications view by swiping down from the top, it crashes. I see the black screen with the apple logo and then it comes back up. As far as I can see, its def. not rebooting/restarting the fone...coz the time it takes on the black screen is minimal compared to a full reboot. My guess is that springboard is crashing. dunno if any1 else is experiencing it?