Wrong ID for browse record (trunk)

Hi!
Trunk version.
I've tried to delete the value of a property and save it. After that I get the error message. I've changed the print to include the type of the variable.

 Traceback (most recent call last):
   File "/home/dukai/workspace/oerp43x-server-microcer/bin/osv/osv.py", line 59, in wrapper
     return f(self, dbname, *args, **kwargs)
   File "/home/dukai/workspace/oerp43x-server-microcer/bin/osv/osv.py", line 119, in execute
     res = pool.execute_cr(cr, uid, obj, method, *args, **kw)
   File "/home/dukai/workspace/oerp43x-server-microcer/bin/osv/osv.py", line 111, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
   File "/home/dukai/oerpwork/workspace-server-run/bin/addons/product/pricelist.py", line 98, in name_get
     for pl in self.browse(cr, uid, ids, context):
   File "/home/dukai/workspace/oerp43x-server-microcer/bin/osv/orm.py", line 419, in browse
     return self._list_class([browse_record(cr, uid, id, self, cache, context=context, list_class=self._list_class, fields_process=fields_process) for id in select], context)
   File "/home/dukai/workspace/oerp43x-server-microcer/bin/osv/orm.py", line 130, in __init__
     assert id and isinstance(id, (int, long,)), _('Wrong ID for the browse record, got %r, type %s, expectedan integer.') % (id, type(id))
 AssertionError: Wrong ID for the browse record, got 0, type <type 'int'>, expected an integer.