[news.eclipse.technology.dltk] 'package require' doesn't works when new

[loulisy@xxxxxxxxx (loulis )]

my dltk version:
dltk-tcl-sdk-R-0.95.1-200809201836-incubation

1. i configurate a tcl interpreter in the preferences page,and configurate 
its lib paths manually;

2. new a tcl project

3. new a source folder and a script, then i use 'package require' with the 
key Alt+/ to show autocomplete package name list ,but there is nothing. 
when i use Ctrl + F1, pop-up a NPE,

4.if i add a user lib to this project , the 'package require' autocomplete 
will work well.

i want to know why? how to reslove it?

NPE:
Caused by: java.lang.NullPointerException
	at 
org.eclipse.dltk.tcl.internal.core.packages.PackagesManager.getPathsForPackage(PackagesManager.java:352)
	at 
org.eclipse.dltk.tcl.internal.ui.text.TclCorrectionProcessor.isFixable(TclCorrectionProcessor.java:160)
	at 
org.eclipse.dltk.tcl.internal.ui.text.TclCorrectionProcessor.isFixable(TclCorrectionProcessor.java:135)
	at 
org.eclipse.dltk.tcl.internal.ui.text.TclCorrectionProcessor.hasCorrections(TclCorrectionProcessor.java:184)
	at 
org.eclipse.dltk.tcl.internal.ui.TclUILanguageToolkit.hasCorrections(TclUILanguageToolkit.java:142)
	at 
org.eclipse.dltk.internal.ui.editor.ScriptAnnotationUtils.hasCorrections(ScriptAnnotationUtils.java:39)
	at 
org.eclipse.dltk.internal.ui.editor.SourceModuleDocumentProvider$ProblemAnnotation.initializeImage(SourceModuleDocumentProvider.java:250)
	at 
org.eclipse.dltk.internal.ui.editor.SourceModuleDocumentProvider$ProblemAnnotation.paint(SourceModuleDocumentProvider.java:303)
	at 
org.eclipse.ui.texteditor.DefaultMarkerAnnotationAccess.paint(DefaultMarkerAnnotationAccess.java:247)
	at 
org.eclipse.jface.text.source.AnnotationRulerColumn.doPaint1(AnnotationRulerColumn.java:767)
	at 
org.eclipse.jface.text.source.AnnotationRulerColumn.doubleBufferPaint(AnnotationRulerColumn.java:518)
	at 
org.eclipse.jface.text.source.AnnotationRulerColumn.redraw(AnnotationRulerColumn.java:797)
	at 
org.eclipse.jface.text.source.AnnotationRulerColumn$6.run(AnnotationRulerColumn.java:784)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
	at 
org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:133)
	... 22 more