[PIPython] errore con query

[Massimo Cecconi]

UPDATE mission_name SET ability = '0' WHERE id_mission = '1'

perchè se faccio questa query mi va a buon fine ma mi restituisce questo 
errore???

Exception _sqlite.DatabaseError: 'cannot rollback - no transaction is 
active' in <bound method Connection.__del__ of <sqlite.main.Connection 
instance at 0x01CC6B48>> ignored

la tabella è questa:

create table mission_name(id_mission integer(11) primary key, 
name_mission varchar(40), ability varchar(2))

un'inserimento:

insert into mission_name(id_mission, name_mission, ability) 
values(\'1\', \'ACQUARIUS\', \'1\')