Swing: GlassPane and the custom painted semitransparent Buttons

Question

I have a short toolbar at the left side of my application. When user points this toolbar, I open a semitransparent full toolbar (I use GlassPane to do it). All except semitransparency works fine.

Here is the screenshot of my example program:

As you see the first button is painted correctly, but all another have completly transparent background.

Here is my code (SSCCE):

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.WindowConstants;
import javax.swing.plaf.basic.BasicButtonUI;
import javax.swing.plaf.metal.MetalLookAndFeel;

/**
 * <code>FlyOutExample</code>.
 */
public class FlyOutExample implements Runnable {

    private static final String[] BUTTONS = {"First button", "Second", "Another button", "Last Button", "End"};

    private static final Color HT_BLUE = new Color(0, 0, 255, 160); // half transparent blue

    private JPanel shortPanel = new JPanel(new GridLayout(5, 1));

    private JPanel fullPanel = new JPanel(new GridLayout(5, 1));

    private JPanel fullPanelWrapper = new JPanel(new BorderLayout());

    private JPanel shortPanelWrapper = new JPanel(new BorderLayout());

    private JFrame frm;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new FlyOutExample());
    }

    @Override
    public void run() {
        try {
            UIManager.setLookAndFeel(MetalLookAndFeel.class.getName());
        } catch (Exception e) {
            e.printStackTrace();
        }
        for (String s : BUTTONS) {
            JButton b = new JButton(s.substring(0, 1));
            b.setBackground(Color.BLUE);
            b.setForeground(Color.RED);
            b.setUI(new BasicButtonUI());
            shortPanel.add(b);
            b = new JButton(s);
            b.setForeground(Color.RED);
            b.setOpaque(false);
            b.setHorizontalAlignment(SwingConstants.LEADING);
            b.setBackground(HT_BLUE);
            b.setUI(new BasicButtonUI() {
                @Override
                public void update(Graphics g, JComponent c) {
                    Color old = g.getColor();
                    g.setColor(HT_BLUE);
                    g.fillRect(0, 0, c.getWidth(), c.getHeight());
                    g.setColor(old);
                    paint(g, c);
                }
            });
            fullPanel.add(b);
        }
        frm = new JFrame("Flyout example");
        shortPanelWrapper.setOpaque(false);
        shortPanelWrapper.add(shortPanel, BorderLayout.NORTH);
        JPanel bluePanel1 = new JPanel();
        bluePanel1.setOpaque(true);
        bluePanel1.setBackground(Color.BLUE);
        shortPanelWrapper.add(bluePanel1);
        fullPanel.setOpaque(false);
        fullPanelWrapper.setOpaque(false);
        fullPanelWrapper.add(fullPanel, BorderLayout.NORTH);
        JPanel bluePanel2 = new JPanel() {
            @Override
            protected void paintComponent(Graphics g) {
                Color old = g.getColor();
                g.setColor(HT_BLUE);
                g.fillRect(0, 0, getWidth(), getHeight());
                g.setColor(old);
            }
        };
        bluePanel2.setOpaque(false);
        fullPanelWrapper.add(bluePanel2);
        MouseListener openListener = new OpenSideBarListener();
        for (Component c : shortPanel.getComponents()) {
            c.addMouseListener(openListener);
        }
        bluePanel1.addMouseListener(openListener);
        MouseListener closeListener = new CloseSideBarListener();
        for (Component c : fullPanel.getComponents()) {
            c.addMouseListener(closeListener);
        }
        bluePanel2.addMouseListener(closeListener);
        JPanel topPanel = new JPanel();
        topPanel.setBackground(Color.GREEN);
        topPanel.setPreferredSize(new Dimension(0, 30));
        JPanel bottomPanel = new JPanel();
        bottomPanel.setBackground(Color.GREEN);
        bottomPanel.setPreferredSize(new Dimension(0, 30));
        frm.add(topPanel, BorderLayout.NORTH);
        frm.add(bottomPanel, BorderLayout.SOUTH);
        frm.add(shortPanelWrapper, BorderLayout.WEST);
        frm.add(new JScrollPane(new JTable(40, 7)));
        frm.pack();
        frm.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frm.setLocationRelativeTo(null);
        frm.setVisible(true);
    }

    private void openPopup() {
        if (shortPanelWrapper.getMousePosition() != null) {
            Container glassPane = (Container) frm.getGlassPane();
            glassPane.setLayout(null);
            fullPanelWrapper.setLocation(shortPanelWrapper.getLocation());
            fullPanelWrapper.setSize(140, shortPanelWrapper.getHeight());
            glassPane.add(fullPanelWrapper);
            glassPane.setVisible(true);
        }
    }

    private void closePopup() {
        if (fullPanelWrapper.getMousePosition() == null) {
            Container glassPane = (Container) frm.getGlassPane();
            glassPane.removeAll();
            glassPane.setVisible(false);
        }
    }

    private class OpenSideBarListener extends MouseAdapter {
        @Override
        public void mouseEntered(MouseEvent e) {
            openPopup();
        }
    }

    private class CloseSideBarListener extends MouseAdapter {
        @Override
        public void mouseExited(MouseEvent e) {
            closePopup();
        }
    }
}

My JDK is: 1.8_91, OS: Windows 7

My question is: what should I do to paint all my buttons correct?

P.S. In real application I have a custom UI for all buttons present in the left toolbar, so please don't remove the UI for my buttons.

UPDATE

I've started the app again (without any changes) and got another bug

Here ist the new picture:

Probably it's a bug of my graphic card?