Ipod Touch

Hey all my ipod is atm 3.1.3 jailbroken but i want to update it 2 4.0.1
but itunes says NONONO UR GONNA DOWNLOAD 4.0.2,
wich i dont want cuz the jailbreak doesnt work on that version
so how i get 4.0.1

Just use the DFU mode trick or whatever to get the firmware selection popup?

Thank you

/thanked