title: Codeigniter form_open_multipart() displays blank in V2.2.0
body: <p>I am using latest version (V2.2.0) of codeigniter and wanted to create a very simple single file upload using the upload class. However I keep getting a blank page when trying to create a form using form_open_multipart and use $this->input->post() as post array. But when I use $_POST everything is fine. I've been looking around, but I can't seem to find out how to make this work.
  I also load the form helper ($this->load->helper('form');)
  The HTML uploadPage.php</p>
  
  <pre><code>&lt;body&gt;
  &lt;?php echo form_open_multipart('upload/theUpload');?&gt;
  &lt;input type="file" name="userfile"&gt;
  &lt;input type="submit" name="submit" value="Upload File"&gt;
  &lt;/form&gt;
  &lt;/body&gt;
  </code></pre>