[6.1] Change Prestations on Task throws error when analytic accounting is installed

[Dieter]

Environment:
OpenERP 6.1 on Ubuntu 10.04 or RedHat 6.2
PostgreSQl 8.4

I installed:
-Project management
- Accounting
- Multiple analytic accounting plans.

I create a project, and create some tasks on them. I assigne the tasks to some users.
The user starts the task.
The users logs some Work (Creates a new entry under 'Task Work' in the form view of the task.
Up until now. Everything works Fine. The Worked time gets created correctly on the analytic account of the project. The timesheet line gets created correctly.

Now, when I go back to the task and worked hours, and I try to modify the number of hours I worked on the task (edit existing logged work line), then save the line and the nsave the task, I get an error on the saving of the task.
Maybe linked to Bug #944079??

Traceback:

Client Traceback (most recent call last):
  File "/opt/openerp/openerp/addons/web/common/http.py", line 180, in dispatch
    response["result"] = method(controller, self, **self.params)
  File "/opt/openerp/openerp/addons/web/controllers/main.py", line 971, in save
    r = m.write([id], data, req.session.eval_context(req.context))
  File "/opt/openerp/openerp/addons/web/common/openerplib/main.py", line 250, in proxy
    args, kw)
  File "/opt/openerp/openerp/addons/web/common/openerplib/main.py", line 117, in proxy
    result = self.connector.send(self.service_name, method, *args)
  File "/opt/openerp/openerp/addons/web/common/http.py", line 611, in send
    raise fault

Server Traceback (most recent call last):
  File "/opt/openerp/openerp/addons/web/common/http.py", line 592, in send
    result = openerp.netsvc.dispatch_rpc(service_name, method, args)
  File "/opt/openerp/openerp/netsvc.py", line 360, in dispatch_rpc
    result = ExportService.getService(service_name).dispatch(method, params)
  File "/opt/openerp/openerp/service/web_services.py", line 586, in dispatch
    res = fn(db, uid, *params)
  File "/opt/openerp/openerp/osv/osv.py", line 167, in execute_kw
    return self.execute(db, uid, obj, method, *args, **kw or {})
  File "/opt/openerp/openerp/osv/osv.py", line 121, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/opt/openerp/openerp/osv/osv.py", line 176, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/opt/openerp/openerp/osv/osv.py", line 164, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/opt/openerp/openerp/addons/project_timesheet/project_timesheet.py", line 222, in write
    return super(task,self).write(cr, uid, ids, vals, context)
  File "/opt/openerp/openerp/addons/project/project.py", line 1050, in write
    result = super(task,self).write(cr, uid, ids, vals, context=context)
  File "/opt/openerp/openerp/osv/orm.py", line 3945, in write
    result += self._columns[field].set(cr, self, id, field, vals[field], user, context=rel_context) or []
  File "/opt/openerp/openerp/osv/fields.py", line 575, in set
    obj.write(cr, user, [act[1]], act[2], context=context)
  File "/opt/openerp/openerp/addons/project_timesheet/project_timesheet.py", line 163, in write
    unit_amount=vals_line['unit_amount'], unit=False, journal_id=vals_line['journal_id'], context=context)
KeyError: 'journal_id'