When I startup the ide, it reports an exception. 
pre-conditions:
I used it in debug mode and compile to a target dir with Ant set to debug mode. 
I am attaching to tomcat-3.2.1 I closed and then opened netbeans again and this 
exception occurred. ( I had not attached yet)
-------------------------------------------------------------------------------
>Log Session: Friday, September 7, 2001 9:59:19 AM PDT
>System Info: 
  Product Version       = NetBeans IDE 3.2 (Build 39)
  IDE Versioning        = IDE/1 spec=1.2.1 impl=39
  Operating System      = Windows 2000 version 5.0 running on x86
  Java; VM; Vendor      = 1.3.1; Java HotSpot(TM) Client VM 1.3.1-b24; Sun 
Microsystems Inc.
  Java Home             = C:\JDK13~1.1\jre
  System Locale         = en_US
  Home Dir; Current Dir = C:\Documents and Settings\rlawson; D:\apps\netbeans
  IDE Install; User Dir = D:\apps\netbeans; d:\apps\netbeans\rlawson
  CLASSPATH             = D:\apps\netbeans\lib\patches\openide-
compat.jar;D:\apps\netbeans\lib\core.jar;D:\apps\netbeans\lib\openide-
fs.jar;D:\apps\netbeans\lib\openide-nodes.jar;D:\apps\netbeans\lib\openide-
util.jar;D:\apps\netbeans\lib\openide.jar;D:\apps\netbeans\lib\ext\jaxp.jar;D:\a
pps\netbeans\lib\ext\jh.jar;D:\apps\netbeans\lib\ext\jpython.jar;D:\apps\netbean
s\lib\ext\parser.jar;D:\apps\netbeans\lib\ext\regexp.jar;D:\apps\netbeans\lib\ex
t\rmi-
ext.jar;D:\apps\netbeans\lib\ext\sax2.jar;D:\apps\netbeans\lib\ext\servlet.jar;D
:\apps\netbeans\lib\ext\xerces.jar;C:\JDK13~1.1\lib\dt.jar;C:\JDK13~1.1
\lib\tools.jar
-------------------------------------------------------------------------------
[INFO] Loaded modules: org.netbeans.core/1 (1.0/unspec); 
org.apache.tools.ant.module/2 (2.2.1/39); org.netbeans.modules.autoupdate/1 
(1.6.1/39); org.netbeans.modules.clazz/1 (1.6.1/39); 
org.netbeans.modules.debugger.core/2 (2.0.1/39); org.netbeans.modules.applet/1 
(1.6.1/39); org.netbeans.modules.debugger.debug/1 (1.8.1/39); 
org.netbeans.modules.debugger.jpda/1 (1.8.1/39); org.netbeans.modules.editor/1 
(1.7.1/39); org.netbeans.modules.html/1 (1.7.1/39); 
org.netbeans.modules.httpserver/1 (1.6.1/39); org.netbeans.modules.extbrowser/1 
(0.2.1/39); org.netbeans.modules.icebrowser/1 (1.6.1/39); 
org.netbeans.modules.image/1 (1.6.1/39); org.netbeans.modules.jarpackager/2 
(1.6.1/39); org.netbeans.modules.java/1 (1.6.1/39); 
org.netbeans.modules.beans/1 (1.6.1/39); org.netbeans.modules.form/2 
(1.6.1/39); org.netbeans.modules.javadoc/1 (1.6.1/39); 
org.netbeans.modules.jndi/1 (1.4/39); org.netbeans.modules.objectbrowser/1 
(1.6.1/39); org.netbeans.modules.projects/1 (1.6.1/39); 
org.netbeans.modules.properties/1 (1.6.1/39); org.netbeans.modules.i18n/1 
(1.7/39); org.netbeans.modules.i18n.form/2 (1.7/39); 
org.netbeans.modules.properties.syntax/1 (1.6.1/39); 
org.netbeans.modules.text/1 (1.6.1/39); org.netbeans.modules.usersguide/1 
(1.7.1/39); org.netbeans.modules.web.core/1 (1.2.1/39); 
org.netbeans.modules.web.core.syntax/1 (1.2.1/39); org.openidex.util/1 
(1.7.1/39); org.netbeans.modules.scripting/1 (1.3.1/39); 
org.netbeans.modules.utilities/1 (1.6.1/39); 
org.netbeans.modules.apisupport.lite/1 (0.1.1/39); org.netbeans.modules.rmi/1 
(1.3.1/39)
path="" :jsp: init
WARNING: C:\JDK13~1.1\jre\classes cannot be opened
org.openide.filesystems.FSException: Root C:\JDK13~1.1\jre\classes does not 
exist.
*********** Exception occurred ************
Fri Sep 07 09:59:53 PDT 2001: java.lang.IllegalArgumentException: A node 
selection cannot contain nodes (setId) not underneath the root (null).
java.lang.IllegalArgumentException: A node selection cannot contain nodes 
(setId) not underneath the root (null).
	at org.openide.explorer.ExplorerManager.setSelectedNodes
(ExplorerManager.java:138)
	at org.openide.explorer.view.ChoiceView$PropertyIL.actionPerformed
(ChoiceView.java:211)
	at javax.swing.JComboBox.fireActionEvent(JComboBox.java:870)
	at javax.swing.JComboBox.selectedItemChanged(JComboBox.java:894)
	at javax.swing.JComboBox.contentsChanged(JComboBox.java:950)
	at javax.swing.AbstractListModel.fireContentsChanged
(AbstractListModel.java:79)
	at org.openide.explorer.view.NodeListModel.setSelectedItem
(NodeListModel.java:167)
	at javax.swing.JComboBox.setSelectedItem(JComboBox.java:415)
	at javax.swing.JComboBox.setSelectedIndex(JComboBox.java:455)
	at javax.swing.JComboBox.contentsChanged(JComboBox.java:970)
	at javax.swing.JComboBox.intervalAdded(JComboBox.java:1007)
	at javax.swing.AbstractListModel.fireIntervalAdded
(AbstractListModel.java:108)
	at org.openide.explorer.view.NodeListModel.added(NodeListModel.java:305)
	at org.openide.explorer.view.NodeListModel$Listener.added
(NodeListModel.java:366)
	at org.openide.explorer.view.VisualizerChildren.added
(VisualizerChildren.java:74)
	at org.openide.explorer.view.VisualizerEvent$Added.run
(VisualizerEvent.java:83)
	at org.openide.explorer.view.VisualizerNode$QP.run
(VisualizerNode.java:442)
	at org.openide.util.Mutex.doEvent(Mutex.java:840)
	at org.openide.util.Mutex.writeAccess(Mutex.java:307)
	at org.openide.explorer.view.VisualizerNode$QP.runSafe
(VisualizerNode.java:426)
	at org.openide.explorer.view.VisualizerNode.childrenAdded
(VisualizerNode.java:231)
	at org.openide.util.WeakListener$Node.childrenAdded
(WeakListener.java:614)
	at org.openide.nodes.Node.fireSubNodesChange(Node.java:563)
	at org.openide.nodes.Children.notifyAdd(Children.java:722)
	at org.openide.nodes.Children.updateAdd(Children.java:699)
	at org.openide.nodes.Children.setEntries(Children.java:479)
	at org.openide.nodes.Children$17.run(Children.java:1616)
	at org.openide.util.Mutex.postRequest(Mutex.java:803)
	at org.openide.util.Mutex.postWriteRequest(Mutex.java:337)
	at org.openide.nodes.Children$Keys.setKeys(Children.java:1624)
	at org.openide.src.nodes.SourceChildren.refreshAllKeys
(SourceChildren.java:270)
	at org.openide.src.nodes.SourceChildren.refreshKeys
(SourceChildren.java:253)
	at org.openide.src.nodes.SourceChildren.access$200
(SourceChildren.java:48)
	at org.openide.src.nodes.SourceChildren$1.run(SourceChildren.java:316)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:154)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:337)
[catch] at java.awt.EventDispatchThread.pumpOneEventForHierarchy
(EventDispatchThread.java:131)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy
(EventDispatchThread.java:98)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:85)