OSGi and Swing

Greetings.

I'm having serious issues in having JFrames declared inside the Activator class or any class used in a service!!!
When i try to start the bundle, there's always an error like this (an example):
"Error executing commang: Activator start error in bundle swing_osgi [183]."
swing_osgi is the bundle and 183 is the ID.

What's the problem????

Code :

---

package pack.server;
 
import java.util.Dictionary;
import java.util.Hashtable;
 
import javax.swing.JFrame;
 
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceRegistration;
 
import pack.iserver.IServer;
 
public class Activator implements BundleActivator {
 
	private ServiceRegistration registration;
	private JFrame f = null;
 
	public void start(BundleContext context) throws Exception {
		Dictionary<String, String> props = new Hashtable<String, String>();
 
		javax.swing.SwingUtilities.invokeLater(new Runnable() {
            // This creates of the application window.
            public void run()
            {
            	System.out.println("hey");
            	f = new JFrame();
                f.setVisible(true);
            }
		});
//		Console c = new Console();
//		c.setSystemInput();
//		c.setSystemOutput();
//		c.setSystemErr();
 
		registration = context.registerService(IServer.class.getName(), 
					new Server(), props);
 
		System.out.println("O servidor foi registado");
 
//		String[] keys = registration.getReference().getPropertyKeys();
//		
//		for(String k: keys){
//			System.out.println(k);
//		}
	}
 
	public void stop(BundleContext context) throws Exception {
        registration.unregister();
    }
 
}

---

strange thing is that "hey" isn't even printed.... wtf

I even tried without using the invokeLater method and causes to happen the same.