cannot approve a leave request

trunk

create a leave request from Human Resources/Leaves/Leave Requests to Approve, confirm it and approve it

Unicity error :

[2011-11-22 08:58:03,867][?] WARNING:orm:No such field(s) in model crm.meeting: note.
[2011-11-22 08:58:03,888][?] ERROR:db.cursor:bad query: insert into "resource_calendar_leaves" (id,"name","holiday_id","resource_id","calendar_id","date_from","date_to",create_uid,create_date) values (2,E'gbhrth',4,1,NULL,NULL,NULL,1,now())
Traceback (most recent call last):
  File "/home/aline/source/server/trunk/openerp/sql_db.py", line 215, in execute
    res = self._obj.execute(query, params)
IntegrityError: null value in column "date_from" violates not-null constraint