J2SE Version (please include all output from java -version flag):
java version "1.6.0-rc"
Java(TM) SE Runtime Environment (build 1.6.0-rc-b96)
Java HotSpot(TM) Client VM (build 1.6.0-rc-b96, mixed mode, sharing)

Does this problem occur on J2SE 1.4.x or 5.0.x ? Yes / No (pick one)
Yes

Operating System Configuration Information (be specific):
Microsoft Windows 2000 [Version 5.00.2195]

InternationalFormatter inserts text incorrectly

1) Run the following code
2) Insert the cursor between the 0 and the %
3) Type 5

Expected: you should see 5%
Actual: you still see 0%

InternationalFormatter is incorrectly inserting the 5 after the % sign (0%5 instead of 05%),
and then attempting to parse it.

import java.text.*;
import javax.swing.*;
import static javax.swing.JFrame.*;
import javax.swing.text.*;

public class Test {
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    NumberFormatter formatter = new NumberFormatter(NumberFormat.getPercentInstance());
    formatter.setAllowsInvalid(false);
    formatter.setCommitsOnValidEdit(true);
    formatter.setOverwriteMode(false);
    JFormattedTextField textField = new JFormattedTextField(formatter);
    textField.setEditable(true);
    textField.setValue(0);
    frame.add(textField);
    frame.pack();
    frame.setVisible(true);
    frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
  }
}