[trunk/7.0][Association]TypeError: %d format: a number is required, not NoneType

[Mehul Mehta(OpenERP)]

Steps to reproduce:

1) Go to Association > Members > click on Members
2) Then you will see the free members in filter (All Member)
3) uncheck that free member field for allmember in filter view
4) Remove filter and on click any members
3) Refresh a members page it gives traceback as below...

Traceback (most recent call last):
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/http.py", line 321, in dispatch
    response["result"] = self._call_function(**self.params)
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/http.py", line 194, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/service/model.py", line 111, in wrapper
    return f(dbname, *args, **kwargs)
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/http.py", line 189, in checked_call
    return self.func(*a, **kw)
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/addons/web/controllers/main.py", line 1115, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/addons/web/controllers/main.py", line 1096, in _call_kw
    names = dict(request.session.model(model).name_get(args[0], **kwargs))
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/http.py", line 561, in proxy
    result = meth(cr, request.uid, *args, **kw)
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/addons/base/res/res_partner.py", line 560, in name_get
    name = record.name
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/osv/orm.py", line 497, in __getattr__
    return self[name]
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/osv/orm.py", line 432, in __getitem__
    raise KeyError('Field %s not found in %s'%(name, self))
  File "/home/odoo/runbot/static/openerp-dev-trunk-27496/server/openerp/osv/orm.py", line 516, in __str__
    return "browse_record(%s, %d)" % (self._table_name, self._id)
TypeError: %d format: a number is required, not NoneType

Note : when any of the member in Association-->Members with check free member field, then traceback will not generate.