--- a/Tools/TRPreviewer.py Sun Aug 29 20:19:29 2010 +0200 +++ b/Tools/TRPreviewer.py Sun Aug 29 20:43:02 2010 +0200 @@ -836,7 +836,8 @@ @param act reference to the action that triggered (QAction) """ idx = act.data() - self.__toggleWidget(self.widgets[idx]) + if idx is not None: + self.__toggleWidget(self.widgets[idx]) def __toggleWidget(self, w): """