error 1600 with iphone 4 and 5.0 custom firmware

[sprite69]

I tried to upgrade to 5.0 but the BB moves to 4.11, and I use gevey, so I canīt do it, so I tried the custom firmware created with Redsnow, and it gives a 1600 error, so I tried to do it normally and it works, but upgrades the babeband, so I downgrade to 4.3.5 and downgrade the baseband, no problem, if I try to do it it gives a 1600 error, so I tried another computer, same error, so I am still no able to upgrade to 5.0, I copy paste the custom IPSW in the folder and still the same error, any idea is welcome

BTW I tried tinyumbrella, but i think does not support iOS5 and gives an error 2005

the phone is in DFU mode