FULL PRODUCT VERSION :
java version "1.6.0_10-beta"
Java(TM) SE Runtime Environment (build 1.6.0_10-beta-b25)
Java HotSpot(TM) Client VM (build 11.0-b12, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.0.6001]

A DESCRIPTION OF THE PROBLEM :
JDeveloper throws NullPointerException when trying to browse file.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Download JDeveloper 10 or 11
2. Go to <JDeveloper>/jdev/bin/jdev.conf
3. Modify the line SetJavaHome to point to the 6u10 JDK (has to be JDK)
4. Safe jdev.conf and run jdev.exe
5. Click the "Open Folder" icon 
6. NPE is thrown.
(This issue is not reproducible with 6u3, 6u4, or 6u5).

Stacktrace:
java.lang.NullPointerException
       at oracle.ide.net.URLChooser$FileView.updateColumnHeader(URLChooser.java
:4716)
       at oracle.ide.net.URLChooser$FileView$FileTable.configureEnclosingScroll
Pane(URLChooser.java:4952)
       at javax.swing.JTable.updateUI(JTable.java:3609)
       at oracle.javatools.controls.nicetable.NiceTable.updateUI(NiceTable.java
:471)
       at javax.swing.JTable.<init>(JTable.java:614)
       at javax.swing.JTable.<init>(JTable.java:552)
       at oracle.javatools.controls.nicetable.NiceTable.<init>(NiceTable.java:2
97)
       at oracle.ide.net.URLChooser$FileView$FileTable.<init>(URLChooser.java:4
738)
       at oracle.ide.net.URLChooser$FileView.$init$(URLChooser.java:4554)
       at oracle.ide.net.URLChooser$FileView.<init>(URLChooser.java:4559)
       at oracle.ide.net.URLChooser.$init$(URLChooser.java:343)
       at oracle.ide.net.URLChooser.<init>(URLChooser.java:434)
       at oracle.ide.net.URLChooser.<init>(URLChooser.java:422)
       at oracle.ide.net.URLChooser.<init>(URLChooser.java:411)
       at oracle.ide.cmd.OpenCommand$OpenURLChooser.<init>(OpenCommand.java:433
)
       at oracle.ide.cmd.OpenCommand.open(OpenCommand.java:125)
       at oracle.ide.cmd.OpenCommand.doit(OpenCommand.java:85)
       at oracle.ide.IdeController.handleEvent(IdeController.java:476)
       at oracle.ide.controller.IdeAction.performAction(IdeAction.java:525)
       at oracle.ide.controller.IdeAction$1.run(IdeAction.java:772)
       at oracle.ide.controller.IdeAction.actionPerformedImpl(IdeAction.java:78
9)
       at oracle.ide.controller.IdeAction.actionPerformed(IdeAction.java:498)
       at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:19
95)
       at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.jav
a:2318)
       at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel
.java:387)
       at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242
)
       at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonL
istener.java:236)
       at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:2
72)
       at java.awt.Component.processMouseEvent(Component.java:6134)
       at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
       at java.awt.Component.processEvent(Component.java:5899)
       at java.awt.Container.processEvent(Container.java:2023)
       at java.awt.Component.dispatchEventImpl(Component.java:4501)
       at java.awt.Container.dispatchEventImpl(Container.java:2081)
       at java.awt.Component.dispatchEvent(Component.java:4331)
       at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4299
)
       at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3963)

       at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3893)
       at java.awt.Container.dispatchEventImpl(Container.java:2067)
       at java.awt.Window.dispatchEventImpl(Window.java:2458)
       at java.awt.Component.dispatchEvent(Component.java:4331)
       at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
       at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThre
ad.java:284)
       at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.
java:184)
       at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThre
ad.java:174)
       at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)

       at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)

       at java.awt.EventDispatchThread.run(EventDispatchThread.java:122) 


REPRODUCIBILITY :
This bug can be reproduced always.

Release Regression From : 6u5
The above release value was the last known release where this 
bug was not reproducible. Since then there has been a regression.