title: java.lang.NoClassDefFoundError on OSGi
body: <p>I have a bundle, with an activator declared. This activator create a JFrame and show it.</p>
  
  <p>Running on Eclipse as Plugin project it works fine. When I put on Felix it doesn't work anymore.
  It shows:
   java.lang.NoClassDefFoundError: com/griep/ui/MainFrame</p>
  
  <p><strong>But MainFrame is located in the same bundle the activator is, as a public class, of course.</strong> I don't understand why the classloader isn't finding the class.</p>
  
  <p>Anyone knows what is happening?</p>