Eclipse Plugin: cannot view preferences

Dear list,

I have installed the lastest SoapUI Eclipse plugin via the update URL mechanism. The plugin installed and I can open the Preferences window and click on soapUI to see the soapUI picture. However, when I click on any of the subsettings 'Editor Settings', 'Global Properties', etc., a window with the message

  Window Title: Could Not Accept Changes
  Window content: The currently displayed page contains invalid values.

appears.

Does anybody know how to resolve this?

I am using soapUI 2.5.1 and Eclipse 3.4.1 on MacOS X.

Thanks,
Kaspar 

P.S. I have tried starting eclipse with '-clean' option, with no success.

P.P.S. Some more info: When I open the soapUI perspective, the soapUI Navigator displays the following error message:

java.lang.LinkageError: loader constraints violated when linking org/w3c/dom/DOMConfiguration class
at org.apache.xerces.parsers.AbstractDOMParser.startDocument(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.startDocument(Unknown Source)
at org.apache.xerces.impl.XMLDocumentScannerImpl.startEntity(Unknown Source)
at org.apache.xerces.impl.XMLVersionDetector.startDocumentParsing(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
at org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:146)
at org.apache.log4j.xml.DOMConfigurator$2.parse(DOMConfigurator.java:612)
at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:711)
at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:618)
at org.apache.log4j.xml.DOMConfigurator.configure(DOMConfigurator.java:743)
at com.eviware.soapui.DefaultSoapUICore.initLog(DefaultSoapUICore.java:385)
at com.eviware.soapui.DefaultSoapUICore.init(DefaultSoapUICore.java:100)
at com.eviware.soapui.DefaultSoapUICore.(DefaultSoapUICore.java:88)
at com.eviware.soapui.SwingSoapUICore.(SwingSoapUICore.java:44)
at com.eviware.soapui.eclipse.SoapUIActivator$1.(SoapUIActivator.java:109)
at com.eviware.soapui.eclipse.SoapUIActivator.initSoapUI(SoapUIActivator.java:109)
at com.eviware.soapui.eclipse.SoapUIActivator.getWorkspace(SoapUIActivator.java:211)
at com.eviware.soapui.eclipse.views.NavigatorView.buildUI(NavigatorView.java:103)
at com.eviware.soapui.eclipse.views.NavigatorView.createPartControl(NavigatorView.java:56)
at org.eclipse.ui.internal.ViewReference.createPartHelper(ViewReference.java:371)
at org.eclipse.ui.internal.ViewReference.createPart(ViewReference.java:230)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:594)
at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:306)
at org.eclipse.ui.internal.ViewPane.setVisible(ViewPane.java:531)
at org.eclipse.ui.internal.presentations.PresentablePart.setVisible(PresentablePart.java:180)
at org.eclipse.ui.internal.presentations.util.PresentablePartFolder.select(PresentablePartFolder.java:270)
at org.eclipse.ui.internal.presentations.util.LeftToRightTabOrder.select(LeftToRightTabOrder.java:65)
at org.eclipse.ui.internal.presentations.util.TabbedStackPresentation.selectPart(TabbedStackPresentation.java:473)
at org.eclipse.ui.internal.PartStack.refreshPresentationSelection(PartStack.java:1256)
at org.eclipse.ui.internal.PartStack.setSelection(PartStack.java:1209)
at org.eclipse.ui.internal.PartStack.showPart(PartStack.java:1608)
at org.eclipse.ui.internal.PartStack.createControl(PartStack.java:649)
at org.eclipse.ui.internal.PartStack.createControl(PartStack.java:576)
at org.eclipse.ui.internal.PartSashContainer.createControl(PartSashContainer.java:568)
at org.eclipse.ui.internal.PerspectiveHelper.activate(PerspectiveHelper.java:271)
at org.eclipse.ui.internal.Perspective.onActivate(Perspective.java:964)
at org.eclipse.ui.internal.WorkbenchPage.setPerspective(WorkbenchPage.java:3568)
at org.eclipse.ui.internal.WorkbenchPage.busySetPerspective(WorkbenchPage.java:1032)
at org.eclipse.ui.internal.WorkbenchPage.access$16(WorkbenchPage.java:1016)
at org.eclipse.ui.internal.WorkbenchPage$18.run(WorkbenchPage.java:3667)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.setPerspective(WorkbenchPage.java:3665)
at org.eclipse.ui.handlers.ShowPerspectiveHandler.openPerspective(ShowPerspectiveHandler.java:152)
at org.eclipse.ui.handlers.ShowPerspectiveHandler.openOther(ShowPerspectiveHandler.java:124)
at org.eclipse.ui.handlers.ShowPerspectiveHandler.execute(ShowPerspectiveHandler.java:63)
at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:281)
at org.eclipse.core.commands.Command.executeWithChecks(Command.java:476)
at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:178)
at org.eclipse.ui.internal.handlers.SlaveHandlerService.executeCommand(SlaveHandlerService.java:253)
at org.eclipse.ui.actions.PerspectiveMenu.runOther(PerspectiveMenu.java:369)
at org.eclipse.ui.actions.PerspectiveMenu$3.runWithEvent(PerspectiveMenu.java:125)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:583)
at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:500)
at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:411)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1561)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1585)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1570)
at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1360)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3482)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3068)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2382)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2346)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2198)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:493)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:288)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:488)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:113)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:193)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:386)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
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.eclipse.equinox.launcher.Main.invokeFramework(Main.java:549)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
at org.eclipse.equinox.launcher.Main.run(Main.java:1236)