title: CSS background-image: url(none) leading to errors in apache log file
body: <p>I have run into a strange problem. When I use:</p>
  
  <pre><code>background-image: url(none);
  </code></pre>
  
  <p>in my css file, it generates an error in the apache log file:</p>
  
  <pre><code>File does not exist: /...../styles/none, referer: http://blabla.com/styles/styles.css
  </code></pre>
  
  <p>I have used the W3C CSS validator and there are no errors (just some warnings about floats needing widths).</p>
  
  <p>I used to have:</p>
  
  <pre><code>background-image: none;
  </code></pre>
  
  <p>but I have changed all instances and the most up-to-date stylesheet is used.</p>
  
  <p>Is this normal behaviour or is it more likely that I have an error somewhere in my stylesheet?</p>