title: rails 3.1.0: images with fingerprint not loaded in production
body: <p>My problem: All images aren't loaded correctly when I start my app in production mode. 
  I see only a placeholder for the image. When I copy the image-url I get "assets/mylogo.png". I miss the fingerprint.</p>
  
  <p>My config:</p>
  
  <p>Gems:</p>
  
  <pre><code>rails 3.1.0
  compass, :git =&gt; 'git://github.com/chriseppstein/compass.git'
  sprockets 2.0.2
  </code></pre>
  
  <p>config/application.rb :</p>
  
  <pre><code>config.assets.enabled = true
  </code></pre>
  
  <p>config/environments/production.rb :</p>
  
  <pre><code>config.cache_classes = true
  config.consider_all_requests_local       = false
  config.action_controller.perform_caching = true
  config.serve_static_assets = false
  config.assets.compress = true
  </code></pre>
  
  <p>After the deploy I run</p>
  
  <pre><code>rake assets:clean
  rake assets:precompile
  </code></pre>
  
  <p>In the public/assets folder are all images (and js, css files) with the fingerprint at the end.</p>
  
  <p>In development mode everything works fine. I can't figure out why the images aren't correctly used.</p>