Dave,

I just bought a Blackberry Storm this past week and at first had no issue using the Camera or the Video camera features until today. I had the very same message that you received " Camera won't start please close other applications and try again" 

 I tried a number of different attempted fixes that failed until........ I deleted the "7 Digital Music store app" that I downloaded yesterday. Whether that is or is not the reason that my camera and video camera wouldn't start is irrelevant to me as they now work since I removed THAT app........ Coincidence?