I'm having problems with my iPhone 3Gs. I had it jailbreaked with Redsn0w, then I restored it to the most update iOS through the newest iTunes. I can't get past the activation menu at all. I tried restoring in DFU mode and still no luck, even with using other SIM cards. I tried downgrading to iOS 5.0 and I get "error 60000ms giving up" on the iPhone screen and I can't edit hosts files at all.
If there is a post about this already, I apologize.