tracback after creating an expense invoice

[Aline (OpenERP)]

tested with demo data, hr_expense module.
- use an existing expense
- approve it,
- create an invoice
- put ahome address to the employee
- create the invoice : traceback

Client Traceback (most recent call last):
  File "/home/aline/source/web/trunk/addons/web/common/http.py", line 154, in dispatch
    response["result"] = method(controller, self, **self.params)
  File "/home/aline/source/web/trunk/addons/web/controllers/main.py", line 726, in call_button
    return {'result': clean_action(req, action)}
  File "/home/aline/source/web/trunk/addons/web/controllers/main.py", line 467, in clean_action
    return fix_view_modes(action)
  File "/home/aline/source/web/trunk/addons/web/controllers/main.py", line 527, in fix_view_modes
    generate_views(action)
  File "/home/aline/source/web/trunk/addons/web/controllers/main.py", line 503, in generate_views
    view_modes, view_id, action))
ValueError: Non-db action dictionaries should provide either multiple view modes or a single view mode and an optional view id.

 Got view modes ['form', 'tree'] and view id (396,) for action {'view_type': 'form', 'res_model': 'account.invoice', 'view_id': [(396,)], 'nodestroy': True, 'view_mode': 'form,tree', 'target': 'current', 'name': u'Supplier Invoices', 'res_id': 59, 'flags': {}, 'context': {'journal_type': 'purchase', 'type': 'out_invoice'}, 'type': 'ir.actions.act_window'}