Scenario: you have a spreadsheet with a named range "Test". Now you insert a new
sheet from file which has the same named range "test". At the moment there will
be a warning that there is a douple named range and that the destination will be
altered. What you get is that the named range on the inserted sheet is lost and
all references on this name are altered to the named range in the document. This
is imho not what the user wants. But if you rename the named range on the
inserted sheet during import this will also happened if there are linked sheets
which gets an update (same code). Possible solutions would be a method for
renaming the name manually or some kind of "smarttag" (as in MSOffice) for
marking the cells which are changed.