On launch running under jdk jdk-7-ea-bin-b135-windows-i586-24_mar_2011, the exception reporter complains "java.lang.IllegalStateException: zip file closed". 

I have a Maven project open.

java.lang.IllegalStateException: zip file closed
	at java.util.zip.ZipFile.ensureOpen(ZipFile.java:595)
	at java.util.zip.ZipFile.getInputStream(ZipFile.java:341)
	at java.util.jar.JarFile.getInputStream(JarFile.java:403)
	at sun.net.www.protocol.jar.JarURLConnection.getInputStream(JarURLConnection.java:162)
	at sun.misc.URLClassPath$Loader$1.getInputStream(URLClassPath.java:553)
	at sun.misc.Resource.cachedInputStream(Resource.java:77)
	at sun.misc.Resource.getByteBuffer(Resource.java:160)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:436)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
[catch] at com.google.inject.internal.util.$FinalizableReferenceQueue$DecoupledLoader.loadFinalizer(FinalizableReferenceQueue.java:257)
	at com.google.inject.internal.util.$FinalizableReferenceQueue.loadFinalizer(FinalizableReferenceQueue.java:178)
	at com.google.inject.internal.util.$FinalizableReferenceQueue.<clinit>(FinalizableReferenceQueue.java:100)
	at com.google.inject.internal.util.$MapMaker$QueueHolder.<clinit>(MapMaker.java:787)
	at com.google.inject.internal.util.$MapMaker$WeakEntry.<init>(MapMaker.java:946)
	at com.google.inject.internal.util.$MapMaker$Strength$1.newEntry(MapMaker.java:312)
	at com.google.inject.internal.util.$MapMaker$StrategyImpl.newEntry(MapMaker.java:498)
	at com.google.inject.internal.util.$MapMaker$StrategyImpl.newEntry(MapMaker.java:419)
	at com.google.inject.internal.util.$CustomConcurrentHashMap$ComputingImpl.get(CustomConcurrentHashMap.java:2029)
	at com.google.inject.internal.Annotations$AnnotationChecker.hasAnnotations(Annotations.java:116)
	at com.google.inject.internal.Annotations.isBindingAnnotation(Annotations.java:180)
	at com.google.inject.Key.ensureIsBindingAnnotation(Key.java:366)
	at com.google.inject.Key.strategyFor(Key.java:353)
	at com.google.inject.Key.get(Key.java:242)
	at org.sonatype.guice.bean.binders.ParameterKeys.<clinit>(ParameterKeys.java:24)
	at org.codehaus.plexus.DefaultPlexusContainer$ContainerModule.configure(DefaultPlexusContainer.java:781)
	at com.google.inject.AbstractModule.configure(AbstractModule.java:59)
	at com.google.inject.spi.Elements$RecordingBinder.install(Elements.java:223)
	at com.google.inject.spi.Elements.getElements(Elements.java:101)
	at com.google.inject.spi.Elements.getElements(Elements.java:78)
	at org.sonatype.guice.bean.binders.MergedModule.configure(MergedModule.java:54)
	at com.google.inject.spi.Elements$RecordingBinder.install(Elements.java:223)
	at com.google.inject.spi.Elements.getElements(Elements.java:101)
	at com.google.inject.internal.InjectorShell$Builder.build(InjectorShell.java:132)
	at com.google.inject.internal.InternalInjectorCreator.build(InternalInjectorCreator.java:103)
	at com.google.inject.Guice.createInjector(Guice.java:95)
	at com.google.inject.Guice.createInjector(Guice.java:72)
	at com.google.inject.Guice.createInjector(Guice.java:62)
	at org.codehaus.plexus.DefaultPlexusContainer.addPlexusInjector(DefaultPlexusContainer.java:450)
	at org.codehaus.plexus.DefaultPlexusContainer.<init>(DefaultPlexusContainer.java:186)
	at org.codehaus.plexus.DefaultPlexusContainer.<init>(DefaultPlexusContainer.java:153)
	at org.netbeans.modules.maven.embedder.EmbedderFactory.createProjectLikeEmbedder(EmbedderFactory.java:211)
	at org.netbeans.modules.maven.embedder.EmbedderFactory.getProjectEmbedder(EmbedderFactory.java:280)
	at org.netbeans.modules.maven.indexer.NexusRepositoryIndexerImpl.createLocalRepositoryPath(NexusRepositoryIndexerImpl.java:208)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:613)
	at org.netbeans.core.startup.layers.BinaryFS$AttrImpl$MethodAndParams.invoke(BinaryFS.java:626)
	at org.netbeans.core.startup.layers.BinaryFS$AttrImpl.getValue(BinaryFS.java:556)
	at org.netbeans.core.startup.layers.BinaryFS$BFSBase.getAttribute(BinaryFS.java:402)
	at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:911)
	at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:844)
	at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:907)
	at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:844)
	at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:772)
	at org.netbeans.modules.maven.indexer.api.RepositoryInfo.createRepositoryInfo(RepositoryInfo.java:102)
	at org.netbeans.modules.maven.indexer.api.RepositoryPreferences.getRepositoryInfos(RepositoryPreferences.java:152)
	at org.netbeans.modules.maven.repository.M2RepositoryBrowserTopComponent.createRootNode(M2RepositoryBrowserTopComponent.java:374)
	at org.netbeans.modules.maven.repository.M2RepositoryBrowserTopComponent.access$500(M2RepositoryBrowserTopComponent.java:76)
	at org.netbeans.modules.maven.repository.M2RepositoryBrowserTopComponent$7.run(M2RepositoryBrowserTopComponent.java:319)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1424)
	at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1968)