[O] Python code block hangs with :session if python-mode is loaded

[Richard Stanton]

I have python-mode (latest version from Launchpad) set up to handle python 
editing in Emacs.

Using orgmode, the following code block runs fine if Ipress C-c C-c, producing 
the (correct) output shown:

#+begin_src python :results output
print "%d + %d = %d" % (2, 3, 2+3)
2**5
#+end_src

#+RESULTS:
: 2 + 3 = 5

If I do not have (require 'python-mode) in my init.el, the following also works 
fine:

#+begin_src python :results output :session
print "%d + %d = %d" % (2, 3, 2+3)
2**5
#+end_src

#+RESULTS:
: 2 + 3 = 5
: 32

However, if (require 'python-mode) is in my init.el file, pressing C-c C-c in 
the second code block causes Emacs to hang with the message "Executing python 
code block". I can get out  by pressing C-g, but it never returns otherwise.