title: Timthumb can't show image after it's uploaded
body: <p>I'm using Wordpress plugin called User Avatar, that uses Timthumb for image display. When I open page to show the image, it gives error 500 in the console, and when I use that image link in new tab, I get following error:</p>
  
  <pre><code>A TimThumb error has occured
  
  The following error(s) occured:
  Could not create the index.html file - to fix this create an empty file named index.html file in the cache directory.
  Could not create cache clean timestamp file.
  
  
  Query String : src=http://my.domain.com/wp-content/uploads/avatars/1/1358504649-bpfull.jpg&amp;w=150&amp;id=1&amp;random=1358504649
  TimThumb version : 2.8.10
  </code></pre>
  
  <p>I persume it's a server error or misconfiguration, everything is being uploaded into folder <code>uploads</code>, then into <code>avatars</code> subfolder, which has <code>0777</code> permission, folder <code>1</code> also has <code>0777</code>.</p>
  
  <p>Insinde, there are both <code>cache</code> and <code>temp</code> folders, both with <code>0777</code> permissions.
  GD Image Lib is enabled on the server.</p>