[O] sort lists by highest level entries

[Rainer Stengele]

Hi,

having

      - [2013-01-24 Do] text
      - [2013-01-25 Fr] text
      - [2013-02-01 Fr] text

which in full view is

      - [2013-01-24 Do] text
        * text
      - [2013-01-25 Fr] text
        #+BEGIN_EXAMPLE
        TEXT
        #+END_EXAMPLE
      - [2013-02-01 Fr] text
        * other stuff


I would like to sort the highest level entries, alphabetically would do
in this case, ending up with

      - [2013-02-01 Fr] text
      - [2013-01-25 Fr] text
      - [2013-01-24 Do] text

which of course in full view is

      - [2013-02-01 Fr] text
        * other stuff
      - [2013-01-25 Fr] text
        #+BEGIN_EXAMPLE
        TEXT
        #+END_EXAMPLE
      - [2013-01-24 Do] text
        * text

org-sort and org-sort-entries does not what I want.
Did I miss something obvious?

Thanks,
Rainer