crash when desactivating an account

Here is the scenario to reproduce the bug :
- take openobject-server trunk and openobject-addons trunk (up-to-date as of today)
- setup a new database with module account_accountant
- Go to Financial management > Configuration > Financial accounting > Accounts > Accounts
- Open a regular account
- Uncheck the "active" field and save
=> CRASH

Here is the backtrace :

Environment Information :
System : Linux-2.6.35-30-generic-x86_64-with-Ubuntu-11.04-natty
OS Name : posix
Distributor ID: Ubuntu
Description: Ubuntu 11.04
Release: 11.04
Codename: natty
Operating System Release : 2.6.35-30-generic
Operating System Version : #54-Ubuntu SMP Tue Jun 7 18:41:54 UTC 2011
Operating System Architecture : 64bit
Operating System Locale : fr_FR.UTF8
Python Version : 2.7.1+
OpenERP-Client Version : 6.1-dev
Last revision No. & ID :1940 launchpad_translations_on_behalf_of_openerp-20110814044436-u41w16uv3zxxjr7i
Traceback (most recent call last):
  File "/home/alexis/new_boite/dev/openobject-server-trunk/openerp/netsvc.py", line 440, in dispatch
    result = ExportService.getService(service_name).dispatch(method, auth, params)
  File "/home/alexis/new_boite/dev/openobject-server-trunk/openerp/service/web_services.py", line 581, in dispatch
    res = fn(db, uid, *params)
  File "/home/alexis/new_boite/dev/openobject-server-trunk/openerp/osv/osv.py", line 118, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/home/alexis/new_boite/dev/openobject-server-trunk/openerp/osv/osv.py", line 172, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/home/alexis/new_boite/dev/openobject-server-trunk/openerp/osv/osv.py", line 163, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/home/alexis/new_boite/dev/openobject-server-trunk/openerp/osv/orm.py", line 3416, in read
    result = self._read_flat(cr, user, select, fields, context, load)
  File "/home/alexis/new_boite/dev/openobject-server-trunk/openerp/osv/orm.py", line 3527, in _read_flat
    res2 = self._columns[val[0]].get(cr, self, ids, val, user, context=context, values=res)
  File "/home/alexis/new_boite/dev/openobject-server-trunk/openerp/osv/fields.py", line 1050, in get
    for field, value in result[id].iteritems():
AttributeError: 'float' object has no attribute 'iteritems'