FULL PRODUCT VERSION :
Java HotSpot(TM) Server VM (build 1.5.0_04-b05, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Linux macdonaldjlinux 2.6.11.4-20a-smp #1 SMP Wed Mar 23 21:52:37 UTC 2005 x86_64 x86_64 x86_64 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
On the Mac and Linux, autoscrolling doesn't work unless you constantly move the mouse. When you try to drag and drop some text from one part of a JTextArea to another, using autoscrolling to move the viewport, you have to shuffle the mouse back and forth to force the scrolling to continue.

This works fine on Windows.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Run the attached program which shows a simple textarea in a scrollpane.
2. Press Enter a bunch of times to cause the vertical scrollbar to appear.
3. Type in some text at the bottom.
4. Highlight the text and initiate a drag.
5. Drag the text up into the autoscrolling region near the top of the window.
6. Note that scrolling stops; you have to trigger more mouse events by wiggling the mouse from side to side to cause scrolling to continue.

This seems the same as what the poster in

http://groups.google.com/group/comp.lang.java.gui/browse_thread/thread/32f57dee374b830d/92aa483e12b72b28?lnk=st&q=java+autoscroll&rnum=1#92aa483e12b72b28

is experiencing.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expected to be able to leave the mouse in the autoscrolling region, without moving it, and have autoscrolling continue.
ACTUAL -
Have to move mouse back and forth to get autoscrolling to continue.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
No error messages.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;

public class Test
{
    public static void main(String[] args)
    {
JFrame frame = new JFrame();
JTextArea t = new JTextArea(100,30);
        t.setAutoscrolls(true);
t.setDragEnabled(true);
final JScrollPane p = new JScrollPane(t);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(p);
frame.setSize(300, 200);
frame.setVisible(true);
    }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
The workaround in the newsgroup message above.