Image to ClipBoard (linux)

Hi all,
I have problems to place an image on the clipboard (ubuntu 10.10). The
code is below, and for example Gimp says that there is nothing in the
clipboard!

import java.awt.*;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import javax.swing.*;

public class testClipboard extends JPanel implements ActionListener{
    private Image image;

    public testClipboard() {
        setPreferredSize(new Dimension(100, 100));
        JButton jb = new JButton("Copy");
        jb.addActionListener(this);
        this.add(jb);
        image = new BufferedImage(100, 100,
BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, 99, 99);
        g.setColor(Color.RED);
        g.drawOval(10, 50, 20, 20);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        copyToClipboard();
    }

    public void copyToClipboard(){
        Clipboard clipboard = Toolkit.getDefaultToolkit
().getSystemClipboard();
        ImageTransferable selection = new ImageTransferable
(image);
        clipboard.setContents(selection, null);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame f = new JFrame();
                f.setDefaultCloseOperation
(JFrame.EXIT_ON_CLOSE);
                f.add(new testClipboard
(),BorderLayout.CENTER);
                f.pack();
                f.setVisible(true);
            }
        });
    }

    class ImageTransferable implements Transferable{
        public ImageTransferable(Image image){
            theImage = image;
        }
        public DataFlavor[] getTransferDataFlavors(){
            return new DataFlavor[]
{ DataFlavor.imageFlavor };
        }
        public boolean isDataFlavorSupported(DataFlavor flavor){
            return flavor.equals(DataFlavor.imageFlavor);
        }
        public Object getTransferData(DataFlavor flavor) throws
UnsupportedFlavorException{
            if (flavor.equals(DataFlavor.imageFlavor)){
                return theImage;
            }
            else{
                throw new UnsupportedFlavorException
(flavor);
            }
        }
        private Image theImage;
    }
}