JTable and JScrollPane

Hi,

a very small demo to tell you my problem (I use Java 1.6).
I have a JTable with 11 columns in a smaller JScrollPane.
The problem is, that I can't put the column "10" between the columns
"8" and "9" with the mouse. It scrolls to the first column.
What is wrong with the JScrollPane.
It works fine with older versions of Java.

Who can help me?

####################

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

public class FixedTable
{
    public static void main(String args[])
    {
        final Object rowData[][] = { { "1", "a", "b", "c", "d", "e", "f",
"g", "h", "i", "j" } };
        final String columnNames[] = { "#", "1", "2", "3", "4", "5", "6",
"7", "8", "9", "10" };
        TableModel mainModel = new AbstractTableModel()
        {
            public final static long serialVersionUID = 20003l;

            public int getColumnCount()
            {
                return columnNames.length - 1;
            }

            public String getColumnName(int column)
            {
                return columnNames[column + 1];
            }

            public int getRowCount()
            {
                return rowData.length;
            }

            public Object getValueAt(int row, int column)
            {
                return rowData[row][column + 1];
            }
        };
        JTable mainTable = new JTable(mainModel);
        mainTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
        JScrollPane scrollPane = new JScrollPane();
        scrollPane.setViewportView(mainTable);
        JFrame frame = new JFrame("Fixed Table");
        frame.setResizable(false);
        frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
        frame.setSize(300, 150);
        frame.setVisible(true);
    }
}