exception from Eclipse 3.0 M3

[zombi]

I found the following exception in eclipse .log, I hope it helps.

!MESSAGE Designer internal error: Property not found: activeTabIndex
!STACK 0
com.swtdesigner.properties.a: Property not found: activeTabIndex
at com.swtdesigner.properties.types.b.<init>(SourceFile:28)
at com.swtdesigner.model.widgets.composites.e.S(SourceFile:35)
at com.swtdesigner.model.q.A(SourceFile:1802)
at com.swtdesigner.gef.o.a(SourceFile:636)
at com.swtdesigner.gef.g.selectionChanged(SourceFile:238)
at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:159)
at org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1016)
at org.eclipse.core.runtime.Platform.run(Platform.java:420)
at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:157)
at org.eclipse.jface.viewers.StructuredViewer.updateSelection(StructuredViewer.java:1282)
at org.eclipse.jface.viewers.StructuredViewer.handleSelect(StructuredViewer.java:652)
at org.eclipse.jface.viewers.StructuredViewer$4.widgetSelected(StructuredViewer.java:676)
at org.eclipse.jface.util.OpenStrategy.fireSelectionEvent(OpenStrategy.java:178)
at org.eclipse.jface.util.OpenStrategy.access$3(OpenStrategy.java:173)
at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:309)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:82)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:953)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:1872)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:1652)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2036)
at org.eclipse.ui.internal.Workbench.run(Workbench.java:2019)
at org.eclipse.core.internal.boot.InternalBootLoader.run(InternalBootLoader.java:858)
at org.eclipse.core.boot.BootLoader.run(BootLoader.java:461)
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:324)
at org.eclipse.core.launcher.Main.basicRun(Main.java:295)
at org.eclipse.core.launcher.Main.run(Main.java:751)
at org.eclipse.core.launcher.Main.main(Main.java:587)

[admin]

What OS and Eclipse version do you use?