Apple OSX Leopard, Netbeans 6, cannot create new java class

Hello,
I have a problem trying to add a new class to my project.
This issue also occurs when I try to create a new project. Te lower
left bar stops at 25%.
I append the stacktrace of the error, I even compiled a report to
issuezilla, finding out that other people have the same issue.

Reading some forums on the web I figured out that it could be a java
sdk version mismatch.
Apple released on 30/4/2008 a java update to version 6, some says it
could have caused this problem.
Anyway I'm looking for some kind of workaround.
here's my configuration:

Product Version: NetBeans IDE 6.0.1 (Build 200801291616)
Java: 1.5.0_13; Java HotSpot(TM) Client VM 1.5.0_13-119
System: Mac OS X version 10.5.2 running on i386; MacRoman; it_IT (nb)
Userdir: /Users/nick2k3/.netbeans/6.0


Can anyone help?

Thank you,
Nicola Maggi

_________________________________________________________________________
java.lang.UnsupportedClassVersionError: Bad version number in .class file
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:675)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:316)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:280)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at org.netbeans.ProxyClassLoader.loadClass(ProxyClassLoader.java:200)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:374)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:242)
        at sun.misc.Service$LazyIterator.next(Service.java:271)
        at javax.script.ScriptEngineManager.initEngines(ScriptEngineManager.java:127)
        at javax.script.ScriptEngineManager.access$000(ScriptEngineManager.java:55)
        at javax.script.ScriptEngineManager$1.run(ScriptEngineManager.java:98)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.script.ScriptEngineManager.init(ScriptEngineManager.java:96)
        at javax.script.ScriptEngineManager.<init>(ScriptEngineManager.java:69)
        at org.netbeans.modules.templates.ScriptingCreateFromTemplateHandler.engine(ScriptingCreateFromTemplateHandler.java:125)
        at org.netbeans.modules.templates.ScriptingCreateFromTemplateHandler.accept(ScriptingCreateFromTemplateHandler.java:67)
        at org.openide.loaders.MultiDataObject.handleCreateFromTemplate(MultiDataObject.java:694)
        at org.openide.loaders.DefaultDataObject.handleCreateFromTemplate(DefaultDataObject.java:159)
        at org.openide.loaders.DataObject$CreateAction.run(DataObject.java:1247)
        at org.openide.loaders.DataObjectPool$1WrapAtomicAction.run(DataObjectPool.java:238)
        at org.openide.filesystems.EventControl.runAtomicAction(EventControl.java:120)
        at org.openide.filesystems.FileSystem.runAtomicAction(FileSystem.java:499)
        at org.openide.loaders.DataObjectPool.runAtomicAction(DataObjectPool.java:250)
        at org.openide.loaders.DataObject.invokeAtomicAction(DataObject.java:861)
        at org.openide.loaders.DataObject.createFromTemplate(DataObject.java:793)
        at org.openide.loaders.DataObject.createFromTemplate(DataObject.java:773)
        at org.netbeans.modules.java.project.NewJavaFileWizardIterator.instantiate(NewJavaFileWizardIterator.java:158)
        at org.openide.loaders.TemplateWizard$InstantiatingIteratorBridge.instantiate(TemplateWizard.java:1025)
        at org.openide.loaders.TemplateWizard.handleInstantiate(TemplateWizard.java:595)
        at org.openide.loaders.TemplateWizard.instantiateNewObjects(TemplateWizard.java:416)
        at org.openide.loaders.TemplateWizardIterImpl.instantiate(TemplateWizardIterImpl.java:248)
        at org.openide.loaders.TemplateWizardIteratorWrapper.instantiate(TemplateWizardIteratorWrapper.java:161)
        at org.openide.WizardDescriptor.callInstantiateOpen(WizardDescriptor.java:1387)
        at org.openide.WizardDescriptor.callInstantiate(WizardDescriptor.java:1341)
        at org.openide.WizardDescriptor.access$1600(WizardDescriptor.java:119)
        at org.openide.WizardDescriptor$Listener$2$1.run(WizardDescriptor.java:1908)
        at org.openide.WizardDescriptor$Listener$2.run(WizardDescriptor.java:1957)
        at org.openide.WizardDescriptor.lazyValidate(WizardDescriptor.java:1316)
        at org.openide.WizardDescriptor.access$1200(WizardDescriptor.java:119)
        at org.openide.WizardDescriptor$Listener.actionPerformed(WizardDescriptor.java:1964)
Caused: java.lang.reflect.InvocationTargetException
        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:585)
        at org.openide.util.WeakListenerImpl$ProxyListener.invoke(WeakListenerImpl.java:449)
Caused: java.lang.reflect.UndeclaredThrowableException
        at $Proxy16.actionPerformed(Unknown Source)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1882)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2202)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.Component.processMouseEvent(Component.java:5602)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3135)
        at java.awt.Component.processEvent(Component.java:5367)
        at java.awt.Container.processEvent(Container.java:2010)
        at java.awt.Component.dispatchEventImpl(Component.java:4068)
        at java.awt.Container.dispatchEventImpl(Container.java:2068)
        at java.awt.Component.dispatchEvent(Component.java:3903)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4256)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3936)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3866)
        at java.awt.Container.dispatchEventImpl(Container.java:2054)
        at java.awt.Window.dispatchEventImpl(Window.java:1791)
        at java.awt.Component.dispatchEvent(Component.java:3903)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:180)
        at java.awt.Dialog$1.run(Dialog.java:535)
        at java.awt.Dialog$2.run(Dialog.java:563)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.awt.Dialog.show(Dialog.java:561)
        at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:834)
        at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:868)
        at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:856)
        at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:104)
        at org.openide.util.Mutex.doEventAccess(Mutex.java:1223)
        at org.openide.util.Mutex.readAccess(Mutex.java:242)
        at org.netbeans.core.windows.services.NbPresenter.show(NbPresenter.java:841)
        at java.awt.Component.show(Component.java:1302)
        at java.awt.Component.setVisible(Component.java:1255)
        at org.openide.loaders.TemplateWizard.instantiateImpl(TemplateWizard.java:502)
        at org.openide.loaders.TemplateWizard.instantiate(TemplateWizard.java:369)
        at org.netbeans.modules.project.ui.actions.NewFile.doPerform(NewFile.java:147)
        at org.netbeans.modules.project.ui.actions.NewFile.actionPerformed(NewFile.java:124)
        at org.netbeans.modules.project.ui.actions.LookupSensitiveAction.actionPerformed(LookupSensitiveAction.java:155)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1882)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2202)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:232)
        at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:231)
        at java.awt.Component.processMouseEvent(Component.java:5602)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3135)
        at java.awt.Component.processEvent(Component.java:5367)
        at java.awt.Container.processEvent(Container.java:2010)
        at java.awt.Component.dispatchEventImpl(Component.java:4068)
        at java.awt.Container.dispatchEventImpl(Container.java:2068)
        at java.awt.Component.dispatchEvent(Component.java:3903)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4256)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3936)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3866)
        at java.awt.Container.dispatchEventImpl(Container.java:2054)
        at java.awt.Window.dispatchEventImpl(Window.java:1791)
        at java.awt.Component.dispatchEvent(Component.java:3903)
[catch] at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:176)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)