title: google analytics js file cached but utm.gif still loaded
body: <p>I use google analytics which uses a file ga.js. This creates a hidden utm.gif file in which parameters are attached and sent to a server (to be included in the google analytics interface)</p>
  
  <p>My understanding is that utm.gif uses a "304 not modified" header, to ensure that the file is always reloaded (rather than cached).</p>
  
  <p>In this case, is it possible that ga.js will not always be loaded (sometimes cached) in my browser, but still the utm.gif works as normal (using the cached ga.js instead of the downloaded ga.js)? In other words, does the ga.js file always need to be downloaded (for every request) in order for utm.gif to have the right parameters?</p>
  
  <p>Cheers</p>
  
  <p>Ke</p>