I have been having a strange problem with my camera rear cam(the one on the back). Seemingly at random. the camera with stop focusing, adjusting, taking pictures, etc. the focus square responds to touch but doesn't do anything and clicking the capture button doesn't do anything. The image doesn't focus and no picture is taken. I have cleared cash, force stopped, restarted and pulled the battery when it happens. Nothing seems to work. I have gone about my business and then tried again later only to have it work. Some times there are days between episodes and sometimes just a few hours. Any ideas? I am at a loss. Thanks!