This may be related to bug 826765, but is _NOT_ the same as bug 830995. In bug 830995, the camera driver thread appears to be deadlocked; in this bug, the camera thinks it is running correctly! If you press the shutter button, the camera takes a picture, and eventually the thumbnail appears at the top of the screen, but the viewfinder remains blank/black. Tapping the home button and tapping the camera icon on the homescreen does not fix the problem. Force-closing the camera and reopening it fixes the problem.
STR: 1. open camera app 2. take photos 3. tap home button to return to home screen 4. press power button to sleep DUT 5. press power button again to wake DUT 6. swipe up and press unlock 7. enter passcode 8. tap camera icon Camera app is now open and the UI is responsive, but the preview is blank.
With unagi 2012/23/01 build: Gaia 1890022 Gecko6a506d1 The previews can be seen ok by tapping on the screen