title: iOS appcache suddenly ignored
body: <p>I have been given the task of building a web-app for a magazine that will be displayed to people using an iPad. Users are encouraged to save it to their home-screen and it has been designed to be usable when offline.</p>
  
  <p>I thought it was working fine, however a client has noticed an issue: after a few minutes, and closing and re-opening the app a bit, the cache resets and it won't load various assets. Some HTML and CSS comes through but when I inspect via the Safari debugging tools, it is complaining that it can't access various images, some javascript and - interestingly - the appcache file itself.</p>
  
  <p>Does anyone have any idea what could be causing iOS/Safari to suddenly ignore my appcache, or at least parts of it?</p>