FULL PRODUCT VERSION :
java version "1.7.0-ea"
java(TM) SE Runtime Environment (build 1/7/0-ea-b29)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.0.6001]

A DESCRIPTION OF THE PROBLEM :
The method setVisible should show a component that has been added but set so it is not visible.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1.  Run the code below, or see it in action at http://www.segal.org/java/ShowComponent/
2.  Click the button "Click to make a hidden button appear"

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
A button "This button was hidden" should appear
ACTUAL -
Using Java 1.7 build 25 the button does not appear.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
Source code:

import java.applet.*;
import java.awt.*;
import java.awt.event.*;

public class ShowComponent extends Applet implements ActionListener {

Button button1, button2;

public void init()
{
    button1 = new Button("Click to make a hidden button appear");
    add(button1);
    button1.addActionListener(this);
    button2 = new Button("This button was hidden");
    add(button2);
    button2.setVisible(false);
}

public void actionPerformed(ActionEvent ae)
{
    if (ae.getSource() == button1)
    {
    button2.setVisible(true);
    invalidate();
    validate();
    }
}
} // END OF Class ShowComponent
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
None.  This last worked in build 23.

Release Regression From : 7
The above release value was the last known release where this 
bug was not reproducible. Since then there has been a regression.