stock picking process crash

In fresh installation with:
Revno
server: 3296
addons: 4306
client: 1785

Change a product with average cost
Create an Purchase Order, approved
Go to receptions, open it
Click on Process, give this error :

[2011-01-18 16:33:54,675][trunk] ERROR:web-services:Uncaught exception
Traceback (most recent call last):
  File "/home/ovnicraft/development/openerp/server/bin/osv/osv.py", line 122, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/home/ovnicraft/development/openerp/server/bin/osv/osv.py", line 176, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/home/ovnicraft/development/openerp/server/bin/osv/osv.py", line 167, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/home/ovnicraft/development/openerp/addons/stock/stock.py", line 664, in action_process
    cr, uid, {}, context=dict(context, active_ids=ids))
  File "/home/ovnicraft/development/openerp/server/bin/osv/orm.py", line 1980, in create
    if self._columns[field]._classic_write:
KeyError: 'move74_product_price'