Comment 7 for bug 769788

This bug is appearing to us, too. First install in this server, so no upgrades:

Environment Information :
System : Linux-2.6.38-8-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 : 2.6.38-8-generic
Operating System Version : #42-Ubuntu SMP Mon Apr 11 03:31:24 UTC 2011
Operating System Architecture : 64bit
Operating System Locale : es_ES.UTF8
Python Version : 2.7.1+
OpenERP-Client Version : 5.0.15
Last revision No. & ID :Bazaar Package not Found !Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/openerp-server/netsvc.py", line 299, in dispatch
    result = LocalService(service_name)(method, *params)
  File "/usr/lib/python2.5/site-packages/openerp-server/netsvc.py", line 77, in __call__
    return getattr(self, method)(*params)
  File "/usr/lib/python2.5/site-packages/openerp-server/service/web_services.py", line 577, in execute
    res = service.execute(db, uid, object, method, *args)
  File "/usr/lib/python2.5/site-packages/openerp-server/osv/osv.py", line 58, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/openerp-server/osv/osv.py", line 119, in execute
    res = pool.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/usr/lib/python2.5/site-packages/openerp-server/osv/osv.py", line 111, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/usr/lib/python2.5/site-packages/openerp-server/addons/poweremail/poweremail_send_wizard.py", line 161, in send_mail
    mailid = self.save_to_mailbox(cr, uid, ids, context)
  File "/usr/lib/python2.5/site-packages/openerp-server/addons/poweremail/poweremail_send_wizard.py", line 195, in save_to_mailbox
    screen_vals = self.read(cr, uid, ids[0], [],context)[0]
KeyError: 0