Q: applicationCache event not raised In Chrome, catching the applicationCache event works (see below) but not in FireFox 17 (even though I see from the info that after allowing the appCache to fill, there is 1.7MB in it). So it is working, but I am not getting the event. Why? (this code is in the first .JS file that is loaded).
function onUpdateReady() {
    window.applicationCache.swapCache();
    if (confirm('A new version of this site is available. Load it?')) {
        window.location.reload();
    }
}
window.applicationCache.addEventListener('updateready', onUpdateReady);
if (window.applicationCache.status === window.applicationCache.UPDATEREADY) {
    onUpdateReady();
}

BTW, I wish FireBug had those neat Resource tabs info on appCache, IndexDB that I have with the Chrome tools. 

A: As far as I found out, the event DOES get fired, but you get an error when you call swapCache, and this prevents finishing the code block.
you can get around this bug by using try-catch
 window.applicationCache.addEventListener('updateready', function() {
  try {window.applicationCache.swapCache();}
  catch(error) {
    console.log(error.code);
  }
  if (confirm('A new version of this site is available. Load it?')) {
    window.location.reload();
  }
}, false);

then everything will work as expected.
