A long while back, before iOS 4.0 came out, I backed up my SHSH with Cydia, in case i wanted to downgrade. I was on 3.1.3 at the time. I recently upgraded to 4.1, but I feel like downgrading again to 3.1.3, because a few of my app store apps are crashing on 4.1 However, when I try to restore to 3.1.3 firmware through itunes, it won't let me. I'm using the same laptop etc. and I changed the my hosts file to redirect to saurik's server before i had upgraded to 3.1.3 too (i think) anyone got any idea as to why i can't go back to 3.1.3 again?