iPhone Occasionally screen is completely black when using camera

[LoneWolf121188]

This happens intermittently, and I can't seem to figure out what triggers it. Occasionally, when I use the camera (either one), the screen is totally black (minus the bar with the shutter button at the bottom and the options at the top). The weird thing is that the camera is actually functioning normally...I get the focus rectangle, and when I hit the shutter it takes an image just fine....it's just that occasionally, the phone isn't displaying the live feed from the camera. This happens whether or not I access the camera from the lockscreen (LockInfo) or BiteSMS. Any ideas as to what's going on?