The following code shows that JListBox.removeSelectionInterval() does
not remove selections. It selects the indices that you want to have
removed and deselects the previously selected indices.

import java.awt.*;
import java.awt.event.*;
import com.sun.java.swing.*;

public class listbox1

{
    public static void main(String[] args)
        {
            String strings[] = { "zero", "one", "two", "three", "four" };
            final JListBox listbox = new JListBox( strings );
            JPanel p = new JPanel();
            p.setLayout(new GridLayout(1,1));
            p.add(listbox);

            listbox.addSelectionInterval(0,1);

            // bug: The following code deselects indices 0 and 1, and
            // selects indices 2 and 3 instead.
            listbox.removeSelectionInterval(2,3);

            WindowListener l = new WindowAdapter() {
                public void windowClosing(WindowEvent e) {System.exit(0);}
            };

            JFrame f = new JFrame("ListBox");
            f.addWindowListener(l);
            f.add(p);
            f.pack();
            f.show();
        }
}