Batch update one2many fails on PO lines

Hi!
Latest from bzr.
Trying to open the one2many batch update dialog I get this traceback:

Traceback (most recent call last):
  File "Koo/Fields/OneToMany/OneToMany.py", line 241, in batchUpdate
    dialog.setup( [], [] )
  File "Koo/Dialogs/BatchUpdateDialog.py", line 111, in setup
    self.screen.new()
  File "Koo/Screen/Screen.py", line 622, in new
    record = self.group.create( default, self.newRecordPosition(), self.group.domain(), ctx )
  File "Koo/Model/Group.py", line 368, in create
    record.fillWithDefaults(domain, ctx)
  File "Koo/Model/Record.py", line 286, in fillWithDefaults
    self.setDefaults(val)
  File "Koo/Model/Record.py", line 355, in setDefaults
    self.group.fieldObjects[fieldname].setDefault(self, value)
  File "Koo/Model/Field.py", line 122, in setDefault
    record.callOnChange(self.attrs['on_change'])
  File "Koo/Model/Record.py", line 508, in callOnChange
    args = [self.evaluateExpression(arg) for arg in arg_names]
  File "Koo/Model/Record.py", line 445, in evaluateExpression
    val = self.evaluateExpression( dom, checkLoad, firstTry=False )
  File "Koo/Model/Record.py", line 447, in evaluateExpression
    raise exception
NameError: name 'parent' is not defined