I always get a NPE when I open any persistence.xml, in source ou vsual mode. The stack trace follows:

eclipse.buildId=I20070625-1500
java.version=1.6.0_03
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=pt_BR
Command-line arguments: -os win32 -ws win32 -arch x86 -data D:\Pessoal\Joao\workspace_eclipse
This is a continuation of log file D:\Pessoal\Joao\workspace_eclipse\.metadata\.bak_0.log
Created Time: 2008-04-07 11:16:45.093

Error
Thu Apr 10 07:19:39 VET 2008
Problems occurred when invoking code from plug-in: "org.eclipse.jface".

java.lang.NullPointerException
at org.eclipse.wst.xml.ui.internal.tabletree.XMLMultiPageEditorPart$StatusLineLabelProvider.getText(XMLMultiPageEditorPart.java:322)
at org.eclipse.wst.xml.ui.internal.tabletree.XMLMultiPageEditorPart.updateStatusLine(XMLMultiPageEditorPart.java:850)
at org.eclipse.wst.xml.ui.internal.tabletree.XMLMultiPageEditorPart$5.selectionChanged(XMLMultiPageEditorPart.java:429)
at org.eclipse.jface.viewers.StructuredViewer$3.run(StructuredViewer.java:842)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at org.eclipse.core.runtime.Platform.run(Platform.java:857)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:46)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:193)
at org.eclipse.jface.viewers.StructuredViewer.firePostSelectionChanged(StructuredViewer.java:840)
at org.eclipse.jface.viewers.StructuredViewer.setSelection(StructuredViewer.java:1642)
at org.eclipse.jface.viewers.TreeViewer.setSelection(TreeViewer.java:1083)
at org.eclipse.jface.viewers.Viewer.setSelection(Viewer.java:392)
at org.eclipse.wst.xml.ui.internal.tabletree.XMLMultiPageEditorPart$TextEditorPostSelectionAdapter.selectionChanged(XMLMultiPageEditorPart.java:233)
at org.eclipse.wst.sse.ui.StructuredTextEditor$6.run(StructuredTextEditor.java:905)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at org.eclipse.wst.sse.ui.StructuredTextEditor$StructuredSelectionProvider.fireSelectionChanged(StructuredTextEditor.java:903)
at org.eclipse.wst.sse.ui.StructuredTextEditor$StructuredSelectionProvider.handlePostSelectionChanged(StructuredTextEditor.java:961)
at org.eclipse.wst.sse.ui.StructuredTextEditor$5.selectionChanged(StructuredTextEditor.java:884)
at org.eclipse.jface.text.TextViewer.firePostSelectionChanged(TextViewer.java:2546)
at org.eclipse.jface.text.TextViewer.firePostSelectionChanged(TextViewer.java:2498)
at org.eclipse.jface.text.TextViewer$5.run(TextViewer.java:2477)
at org.eclipse.swt.widgets.Display.runTimer(Display.java:3745)
at org.eclipse.swt.widgets.Display.messageProc(Display.java:2967)
at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:2264)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3291)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2389)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2353)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2219)
at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:466)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:461)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:106)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:153)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:363)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:504)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:443)
at org.eclipse.equinox.launcher.Main.run(Main.java:1169)