AttributeError: 'str' object has no attribute 'update' under New Supplier Invoice

openerp 5rc3
Dialog
->Financial Management -> Invoices -> Supplier Invoice -> New Supplier Invoice

I wanted to fill lines with products. If i a product via F2 in the "product" filed under invoice lines i got this error:

Traceback (most recent call last):
  File "/home/vockst/openerp/server/bin/netsvc.py", line 421, in run
    result_from_method = method(*msg[2:])
  File "/home/vockst/openerp/server/bin/service/web_services.py", line 427, in execute
    res = service.execute(db, uid, object, method, *args)
  File "/home/vockst/openerp/server/bin/osv/osv.py", line 59, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/home/vockst/openerp/server/bin/osv/osv.py", line 120, in execute
    res = pool.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/home/vockst/openerp/server/bin/osv/osv.py", line 112, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/home/vockst/openerp/server/bin/addons/account/invoice.py", line 931, in product_id_change
    context.update({'lang': lang})
AttributeError: 'str' object has no attribute 'update'