Screenshots and home screen freezes and the native camera app turning completely black are the most common. Thought it was maybe a dodgy app in the background causing it, or a memory problem, but have been able to replicate the problem with a factory install and only Apple apps. Thought I could live with it, or would be patched quickly (assumed it was a known issue) but now I'm thinking to take it to the Apple store - it's been about 3 weeks now of this. Bought it from O2 though, a carrier. What would you do in this situation?