If I do the following:
- Tools->Update Center
- Click on the ... button next to the download centers drop down list
- Click cancel
- Click the Proxy configuration button

I get the exception listed below.  Sometimes it happens immediately, sometimes 
it only happens when I cancel the proxy settings dialog.  When I close the 
exception dialog and cancel the auto update wizard, most of the entries on the 
Tools menu have disappeared.

I haven't had this happen to me when I haven't clicked on '...' and displayed 
the update center's server URL first.

The Exception dialog just contains "Exception in setter method of property:" 
with no property name, and the corresponding details are

Tue Oct 23 18:05:13 BST 2001: 
org.openide.explorer.propertysheet.PropertyDetails$ExceptionHack: 
java.lang.reflect.InvocationTargetException: java.lang.NullPointerException
        at org.openide.ServiceType$Handle.<init>(ServiceType.java:274)
        at org.netbeans.modules.autoupdate.Settings.setAutoupdateType
(Settings.java:115)
        at java.lang.reflect.Method.invoke(Native Method)
        at org.openide.explorer.propertysheet.DefaultPropertyModel.setValue
(DefaultPropertyModel.java:130)
        at org.openide.explorer.propertysheet.PropertyPanel$Property.setValue
(PropertyPanel.java:454)
        at org.openide.explorer.propertysheet.PropertyDetails.setPropertyValue
(PropertyDetails.java:185)
        at org.openide.explorer.propertysheet.PropertyDisplayer.setPropertyValue
(PropertyDisplayer.java:841)
        at org.openide.explorer.propertysheet.PropertyDisplayer.setAsText
(PropertyDisplayer.java:810)
        at 
org.openide.explorer.propertysheet.PropertyDisplayer$WriteComponentListener.chan
geValue(PropertyDisplayer.java:1109)
        at 
org.openide.explorer.propertysheet.PropertyDisplayer$WriteComponentListener.focu
sLost(PropertyDisplayer.java:1086)
        at java.awt.AWTEventMulticaster.focusLost(AWTEventMulticaster.java:171)
        at java.awt.Component.processFocusEvent(Component.java:3642)
        at javax.swing.JComponent.processFocusEvent(JComponent.java:1980)
        at java.awt.Component.processEvent(Component.java:3535)
        at java.awt.Container.processEvent(Container.java:1164)
        at java.awt.Component.dispatchEventImpl(Component.java:2593)
        at java.awt.Container.dispatchEventImpl(Container.java:1213)
        at java.awt.Component.dispatchEvent(Component.java:2497)
        at java.awt.LightweightDispatcher.setFocusRequest(Container.java:2076)
        at java.awt.Container.proxyRequestFocus(Container.java:1335)
        at java.awt.Container.proxyRequestFocus(Container.java:1330)
        at java.awt.Container.proxyRequestFocus(Container.java:1330)
        at java.awt.Container.proxyRequestFocus(Container.java:1330)
        at java.awt.Container.proxyRequestFocus(Container.java:1330)
        at java.awt.Container.proxyRequestFocus(Container.java:1330)
        at java.awt.Container.proxyRequestFocus(Container.java:1330)
        at java.awt.Container.proxyRequestFocus(Container.java:1330)
        at java.awt.Component.requestFocus(Component.java:4174)
        at javax.swing.JComponent.grabFocus(JComponent.java:915)
        at javax.swing.JComponent.requestFocus(JComponent.java:897)
        at javax.swing.plaf.basic.BasicButtonListener.mousePressed
(BasicButtonListener.java:207)
        at java.awt.Component.processMouseEvent(Component.java:3712)
        at java.awt.Component.processEvent(Component.java:3544)
        at java.awt.Container.processEvent(Container.java:1164)
        at java.awt.Component.dispatchEventImpl(Component.java:2593)
        at java.awt.Container.dispatchEventImpl(Container.java:1213)
        at java.awt.Component.dispatchEvent(Component.java:2497)
        at java.awt.LightweightDispatcher.retargetMouseEvent
(Container.java:2451)
[catch] at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2210)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2125)
        at java.awt.Container.dispatchEventImpl(Container.java:1200)
        at java.awt.Window.dispatchEventImpl(Window.java:926)
        at java.awt.Component.dispatchEvent(Component.java:2497)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:339)
        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)