[O] Babel blocks not indented

[Julien Cubizolles]

I'm new to babel and I'm experiencing a strange problem. A
src_block created with "<s TAB" is not indented as the heading it's
in. Here is an example:

--8<---------------cut here---------------start------------->8---
**** Export fichier texte
#+BEGIN_SRC python
  import numpy
  numpy.savetxt("foo.csv", a, delimiter=",")
#+END_SRC
--8<---------------cut here---------------end--------------->8---

The python code should be indented below the heading title "Export
fichier texte".

Julien.