build : Merlin-rc b89
OS : Windows japanese 98 2nd, 2k, NT SP6 and XP FCS.
        Windows english XP RC2 and 2k multilanguage

Inputting some character in JTextArea and JEditorPane, inputted character are not displayed correctly.

Steps to reproduce;
1. launch Notepad demo ($JAVAHOME/demo/jfc/Notepad/Notepad.jar)
   % java -jar Notepad.jar
  or
   launch JTextAreaTest(attached)
   % java JTextAreaTest
2. comes up dialog and click text area.
3. input some characters in 10, 15 or 20 lines like below.
  
    ex) abcdeffkditurtoirtuoeitrjlgf
         akjfdkjfsslktritrktjrjtrkjrlkjt
         akdfjlskfjdlskglkdsgjfgjkfjgkfj
         ajkdfldskflddgksfjglkjdkgjkdkfgl
           .
           .
           .

Then, you can see the problem.

The first several lines are displayed correctly, however, if arournd the 10th line or more, suddenly the inputted characters disappear.
Keeping inputting more, the caret is not placed on the correct position.

It seems that this problem occurs if user inputs many characters in many lines.


* This problem does not occur on b88.
  Therefore, this is a regression bug.

* The problem is reproducible on Windows XP English version and 2k multilanguage with English locale.

* This problem does not occur on Solaris.

===============================================================================

You can see another symptom on the same environment.

First, input many text until a vertical scrollbar appears.
   ex) abc
       abc
       abc
       abc
        .
        .
        .
Scrolling with the UP/DOWN arrow keys erase a character on the cursor,
or rewrite it at wrong position.

Inputting text strings at least 2 lines until a horizontal scrollbar appears
and scrolling with the RIGHT/LEFT arrow key causes the same problem.