title: File to import not found or unreadable: compass/css3/animation
body: <p>I need to use animation wih compass, so I try to use like said in doc: <a href="http://compass-style.org/reference/compass/css3/animation/">http://compass-style.org/reference/compass/css3/animation/</a></p>
  
  <p>I put at top of my file:</p>
  
  <pre><code>@import "compass/css3/animation";
  </code></pre>
  
  <p>but I have error: </p>
  
  <pre><code> File to import not found or unreadable: compass/css3/animation.
  </code></pre>
  
  <p>I have the latest version of compass and rails-compass gem, so I don't know where is my mistake?</p>
  
  <p>thx.</p>