Java SE (Java Platform, Standard Edition)

Hello,

this spinner beeps when using the arrow keys or clicking the UP or DOWN
button. Only after modifying a cipher, one can spin as expected. Where is the error?
The behaviour is the same under jdk 1.6.26 and 1.7.

import java.awt.*;
import java.util.*;
import javax.swing.*;

public class DateSpinner extends JFrame {
  JSpinner spin;

  public DateSpinner() {
    setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    setSize(200,100);
    setLayout(null);
    Date date= new Date();
    spin= new JSpinner(new SpinnerDateModel(
				date, date, null, Calendar.DAY_OF_MONTH));
    spin.setEditor(new JSpinner.DateEditor(spin, "dd.MM.yyyy"));
    spin.setBounds(50,20, 80,25);
    add(spin);
    setVisible(true);
  }

  public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
      public void run() {
	new DateSpinner();
      }
    });
  }
}