Problem - cannot display rows correctly in jTable

There seems to be a problem with processing and inserting large (>2000)
amounts of data into jtable.

I read single rows from a database, do some processing and use
insertrow() to feed them to jtable. They get to be displayed (UI) as
soon ALL rows are done and over with, whereas the desired functionality
is to be displayed as soon as they are entered (row by row).

Need help as this is turning up to take too much time to figure out.
Have tried several approaches with no luck.

Some code is listed below:

// Create staff
  DefaultTableModel model_matrix = new DefaultTableModel();
  JScrollPane jScrollPane_matrix = new JScrollPane();
  JTable jTable_matrix = new JTable(model_matrix) {
    public boolean isCellEditable(int rowIndex, int vColIndex) {
      return false;
    }

// Add some columns
      model_matrix.addColumn("Timestamp");
      model_matrix.addColumn("hpic");

//Insert rows
while (more db rows...){
            read row...
            process row...
            //insert row
            i = model_matrix.getRowCount();
            model_matrix.insertRow(i, new Object[] {timestamp, HPIC});
            model_matrix.fireTableRowsInserted(i,i); setSelectedRow(i);

}

Need help, thanxs