Thanks for the quick response..
how would i know if i have the shsh files?
where can i find the 1600 solution guide?

Hi Kiran... I've tried the 3.1.2 Custom Firmware activated for OTher carrier but failing , I am getting 1600 error.
I have 32gb 3GS 3.1.2 OTB.
Running Vista
I started from iTunes 9 to 9.1 - Now my iTune is 9.1.1.12 and still error 1600
Please advise.
Thanks.