stacks around user profile urls

Got these exceptions, have indeed some ugly and improbalbe archived 
messages but....

Objet 	[Django] ERROR (EXTERNAL IP): Internal Server Error: 
/hyperkitty/accounts/profile/
De 	<root@localhost>
À 	<root@localhost>, nicolas(a)karageuzian.comAdd contact
Date 	Aujourd'hui 21:18

Traceback (most recent call last):

   File 
"/home/mailman/py27/lib/python2.7/site-packages/django/core/handlers/base.py", 
line 115, in get_response
     response = callback(request, *callback_args, **callback_kwargs)

   File 
"/home/mailman/py27/lib/python2.7/site-packages/django/contrib/auth/decorators.py",

line 25, in _wrapped_view
     return view_func(request, *args, **kwargs)

   File "/home/mailman/hyperkitty/hyperkitty/views/accounts.py", line 
101, in user_profile
     request.user.first_name, request.user.last_name)

   File "/home/mailman/mailman.client/src/mailmanclient/_client.py", 
line 634, in display_name
     self._info['display_name'] = value

TypeError: 'NoneType' object does not support item assignment

-------- Message original --------
Objet: [Django] ERROR (EXTERNAL IP): Internal Server Error: 
/hyperkitty/user/288337319251703833024167193486004604413/
Date: 2013-12-02 20:54
De: root@localhost
À: root@localhost, nicolas(a)karageuzian.com

Traceback (most recent call last):

   File 
"/home/mailman/py27/lib/python2.7/site-packages/django/core/handlers/base.py", 
line 115, in get_response
     response = callback(request, *callback_args, **callback_kwargs)

   File "/home/mailman/hyperkitty/hyperkitty/views/accounts.py", line 
275, in public_profile
     subscriptions = get_subscriptions(store, client, mm_user)

   File "/home/mailman/hyperkitty/hyperkitty/lib/mailman.py", line 64, 
in get_subscriptions
     posts_count = store.get_message_count_by_user_id(

AttributeError: 'StormStore' object has no attribute 
'get_message_count_by_user_id'

Objet 	[Django] ERROR (EXTERNAL IP): Internal Server Error: 
/hyperkitty/accounts/profile/subscriptions
De 	<root@localhost>
À 	<root@localhost>, nicolas(a)karageuzian.comAdd contact
Date 	Aujourd'hui 21:17

Traceback (most recent call last):

   File 
"/home/mailman/py27/lib/python2.7/site-packages/django/core/handlers/base.py", 
line 115, in get_response
     response = callback(request, *callback_args, **callback_kwargs)

   File 
"/home/mailman/py27/lib/python2.7/site-packages/django/contrib/auth/decorators.py",

line 25, in _wrapped_view
     return view_func(request, *args, **kwargs)

   File "/home/mailman/hyperkitty/hyperkitty/views/accounts.py", line 
252, in subscriptions
     subscriptions = get_subscriptions(store, mm_client, mm_user)

   File "/home/mailman/hyperkitty/hyperkitty/lib/mailman.py", line 64, 
in get_subscriptions
     posts_count = store.get_message_count_by_user_id(

AttributeError: 'StormStore' object has no attribute 
'get_message_count_by_user_id'