title: "No protocol specified" when running a sudo/su app on Ubuntu Linux
body: <p>I try to run the iReport 5.6 on Ubuntu and Java 7, using the command:</p>
  
  <pre><code>$ sudo iReport-5.6.0/bin/ireport
  No protocol specified.
  </code></pre>
  
  <p>I get an error. When I try run it without <code>sudo</code>, I get a permission denied error and an alert that the file Preferences on Default System are read only.</p>