Exporting code to latex

When exporting to LaTeX ipython code blocks, only the results get exported, even though ~:exports both~ is explicitly included.

The following sample org file fails to output the ipython code, but outputs only the results:
'''
# +LATEX_CLASS: article
- tema 1
some text and ipython code
# initialize ipython kernel
#+BEGIN_SRC ipython :session :exports both
acf_time = 10.45678
#+END_SRC
# +RESULTS:
- tema 2
more ipython text and code
# +name: ipython_acf
# +BEGIN_SRC ipython :session :exports both

'{:.3f}'.format(acf_time)
# +END_SRC
- tema 3
and now python code
# +name: python_acf
# +BEGIN_SRC python :session :exports both

'{:.3f}'.format(acf_time)
# +END_SRC
# +RESULTS: python_acf

: 10.457

The acf time in ipython export is call_ipython_acf()

the acf time in python export is call_python_acf()
'''
The produced pdf is included below.
[exportacion.pdf](https://github.com/gregsexton/ob-ipython/files/43067/exportacion.pdf)