Our camera had the same problem for awhile. Check your PWM connections; they tend to jar loose. I would suggest zip tying the cables to the holes that are pre-drilled into the camera mount. They stay in much better that way. Also, we discovered that you can get power to the camera through the first Digital port on the RC. FYI: The 7.2 V backup battery can drain fairly quickly, so make sure you charge it regularly. If the camera still isn't working, try restarting the RC and OI completely. Our camera worked fine once we did that.
