Strange Exception within TypeMock

Hi,

when I tell TypeMock not to mock the constructor of a type and create a new instance of that type I get the following strange Exception:

TestCase 'ValidationDBEditorPluginTest.Xxx.Validator.DatabaseEditor.VDBTreeViewTest.SetStateIcons_Test' failed: System.ArgumentException : Item has already been added.  Key in dictionary: "TypeMock.e"  Key being added: "TypeMock.e"
   at System.Collections.Hashtable.Insert(Object key, Object nvalue, Boolean add)
   at System.Collections.Hashtable.Add(Object key, Object value)
   at TypeMock.c.a(String A_0, Object A_1, Object A_2)
   at TypeMock.MockManager.a(String A_0, String A_1, Object A_2, Object A_3)
   at TypeMock.InternalMockManager.isMocked(Object that, String typeName, String methodName, Object methodParameters)
   e:scmwscoladacarddesigner_maindevelopmentssembliesalidationdbeditorpluginxxxalidatordatabaseeditor
odebase.cs(46,0): at Xxx.Validator.DatabaseEditor.NodeBase..ctor()
   at ValidationDBEditorPluginTest.Xxx.Validator.DatabaseEditor.Testnode..ctor()
   e:scmwscoladacarddesigner_main	estssembliesalidationdbeditorplugin
unitformstestxxxalidatordatabaseeditordbtreeviewtest.cs(228,0): at ValidationDBEditorPluginTest.Xxx.Validator.DatabaseEditor.VDBTreeViewTest.SetStateIcons_Test()

Does anybody know what I am doing wrong?