JTable: adding one to JPanel and it doesn't display itself

Monday morning, where I am, this means that I am not failing in Java Swing! But, in all seriousness, I can’t understand why my dynamically created JTable refuses to show itself after adding to JPanel on JFrame and will be very grateful for any help in isolating this unpleasant problem. As you can see from the code, I have named a dozen different methods, but it seems that I can’t get the right solution to display it ... maybe I am missing one?

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package energizingemerald;


import javax.swing.*;
import java.awt.Dimension;
/**
 *
 * @author Ryan
 */
public class SectionManagerFrame extends javax.swing.JFrame {

    /**
     * Creates new form SectionManagerFrame
     */
    public SectionManagerFrame() {
        initComponents();


    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jButton_Cancel = new javax.swing.JButton();
        jButton_OK = new javax.swing.JButton();
        jLabel_Title = new javax.swing.JLabel();
        jLabel_Description = new javax.swing.JLabel();
        jTextField_Title = new javax.swing.JTextField();
        jScrollPane2 = new javax.swing.JScrollPane();
        jTextArea_Description = new javax.swing.JTextArea();
        jButton_Remove = new javax.swing.JButton();
        jButton_Add = new javax.swing.JButton();
        jButton_Edit = new javax.swing.JButton();
        jPanel_Grid = new javax.swing.JPanel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        addWindowListener(new java.awt.event.WindowAdapter() {
            public void windowOpened(java.awt.event.WindowEvent evt) {
                formWindowOpened(evt);
            }
        });

        jButton_Cancel.setText("Cancel");
        jButton_Cancel.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mouseClicked(java.awt.event.MouseEvent evt) {
                jButton_CancelMouseClicked(evt);
            }
        });

        jButton_OK.setText("OK");
        jButton_OK.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mouseClicked(java.awt.event.MouseEvent evt) {
                jButton_OKMouseClicked(evt);
            }
        });

        jLabel_Title.setText("Review Title:");

        jLabel_Description.setText("Review Description:");

        jTextArea_Description.setColumns(20);
        jTextArea_Description.setRows(5);
        jScrollPane2.setViewportView(jTextArea_Description);

        jButton_Remove.setText("Remove");

        jButton_Add.setText("Add");

        jButton_Edit.setText("Edit");

        javax.swing.GroupLayout jPanel_GridLayout = new javax.swing.GroupLayout(jPanel_Grid);
        jPanel_Grid.setLayout(jPanel_GridLayout);
        jPanel_GridLayout.setHorizontalGroup(
            jPanel_GridLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 0, Short.MAX_VALUE)
        );
        jPanel_GridLayout.setVerticalGroup(
            jPanel_GridLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 268, Short.MAX_VALUE)
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addGap(122, 122, 122)
                        .addComponent(jButton_Cancel)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jButton_OK)
                        .addGap(0, 0, Short.MAX_VALUE))
                    .addGroup(layout.createSequentialGroup()
                        .addContainerGap()
                        .addComponent(jPanel_Grid, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addGap(18, 18, 18)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                            .addComponent(jButton_Remove, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(jButton_Add, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(jButton_Edit, javax.swing.GroupLayout.PREFERRED_SIZE, 71, javax.swing.GroupLayout.PREFERRED_SIZE)))
                    .addGroup(layout.createSequentialGroup()
                        .addContainerGap()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jLabel_Description)
                            .addComponent(jLabel_Title))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jTextField_Title))
                    .addGroup(layout.createSequentialGroup()
                        .addContainerGap()
                        .addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 587, Short.MAX_VALUE)))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel_Title)
                    .addComponent(jTextField_Title, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jLabel_Description)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 196, Short.MAX_VALUE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(jButton_Add)
                        .addGap(3, 3, 3)
                        .addComponent(jButton_Edit)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jButton_Remove))
                    .addComponent(jPanel_Grid, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jButton_Cancel)
                    .addComponent(jButton_OK))
                .addContainerGap())
        );

        pack();
    }// </editor-fold>                        

    private void jButton_CancelMouseClicked(java.awt.event.MouseEvent evt) {                                            
        // TODO add your handling code here:
        this.setVisible(false);
        this.dispose();
    }                                           

    private void jButton_OKMouseClicked(java.awt.event.MouseEvent evt) {                                        
        // TODO add your handling code here:
    }                                       

    private void formWindowOpened(java.awt.event.WindowEvent evt) {                                  
        // TODO add your handling code here:
        //ManagerDataModel newManagerDataModel = new ManagerDataModel();
        /*
        newManagerDataModel.AddColumn("Section Name");
        newManagerDataModel.AddColumn("Section Type");
        newManagerDataModel.AddColumn("# of Particles");
        newManagerDataModel.AddRow(new String[]{"Test","Test","Test"});
        */
        jTable_Sections = new JTable(5, 5);
        //jTable_Sections.setPreferredScrollableViewportSize(new Dimension(500, 500));
        jTable_Sections.setMinimumSize(new Dimension(200, 200));
        jTable_Sections.setFillsViewportHeight(true);
        jScrollPane_Sections = new JScrollPane(jTable_Sections);
        jScrollPane_Sections.setMinimumSize(new Dimension(200, 200));
        jPanel_Grid.add(jTable_Sections);
        jPanel_Grid.add(jScrollPane_Sections);
        jPanel_Grid.validate();
        jPanel_Grid.repaint();
        this.validate();
        this.pack();
        this.repaint();


    }                                 
    private JTable jTable_Sections;
    private JScrollPane jScrollPane_Sections;
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(SectionManagerFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(SectionManagerFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(SectionManagerFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(SectionManagerFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new SectionManagerFrame().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton_Add;
    private javax.swing.JButton jButton_Cancel;
    private javax.swing.JButton jButton_Edit;
    private javax.swing.JButton jButton_OK;
    private javax.swing.JButton jButton_Remove;
    private javax.swing.JLabel jLabel_Description;
    private javax.swing.JLabel jLabel_Title;
    private javax.swing.JPanel jPanel_Grid;
    private javax.swing.JScrollPane jScrollPane2;
    private javax.swing.JTextArea jTextArea_Description;
    private javax.swing.JTextField jTextField_Title;
    // End of variables declaration                   
}