有关eclipse的preferences

今天打开eclipse，发现点击window菜单下的preferences，出来的界面一篇空白，所有的插件信息全部不见了，请各位大虾指点:
看eclipse的log，内容如下：
!SESSION 十一月 10, 2003 10:44:59.106 ---------------------------------------------
java.version=1.4.1_05
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=zh_CN
Command-line arguments: -os win32 -ws win32 -arch x86 -install file:C:/eclipse/
!ENTRY org.eclipse.ui 4 4 十一月 10, 2003 10:44:59.116
!MESSAGE Unhandled exception caught in event loop.
!ENTRY org.eclipse.ui 4 0 十一月 10, 2003 10:44:59.116
!MESSAGE java.lang.NullPointerException
!STACK 0
java.lang.NullPointerException
at org.eclipse.ui.internal.WorkbenchPlugin.createExtension(WorkbenchPlugin.java:149)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceNode.createPage(WorkbenchPreferenceNode.java:49)
at org.eclipse.jface.preference.PreferenceDialog.showPage(PreferenceDialog.java:993)
at org.eclipse.jface.preference.PreferenceDialog.selectSavedItem(PreferenceDialog.java:703)
at org.eclipse.jface.preference.PreferenceDialog$3.run(PreferenceDialog.java:329)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:69)
at org.eclipse.jface.preference.PreferenceDialog.createContents(PreferenceDialog.java:324)
at org.eclipse.jface.window.Window.create(Window.java:302)
at org.eclipse.ui.internal.OpenPreferencesAction.run(OpenPreferencesAction.java:51)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:842)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:456)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetEvent(ActionContributionItem.java:403)
at org.eclipse.jface.action.ActionContributionItem.access$0(ActionContributionItem.java:397)
at org.eclipse.jface.action.ActionContributionItem$ActionListener.handleEvent(ActionContributionItem.java:72)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:81)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:840)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:1838)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:1545)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1402)
at org.eclipse.ui.internal.Workbench.run(Workbench.java:1385)
at org.eclipse.core.internal.boot.InternalBootLoader.run(InternalBootLoader.java:858)
at org.eclipse.core.boot.BootLoader.run(BootLoader.java:461)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.eclipse.core.launcher.Main.basicRun(Main.java:291)
at org.eclipse.core.launcher.Main.run(Main.java:747)
at org.eclipse.core.launcher.Main.main(Main.java:583)