So, I tried every which way to JB my iPhone 3G 3.1.3 last night. I ran the sn0wbreeze firmware checker to see if I could JB, which it said I could. I'm not concerned with unlocking or tethering... I'm already on AT&T, I just want to install Cydia apps. I restored to 3.1.2 and successfully JB'ed the phone with blackra1n, however my AT&T service was GONE. No carrier logo, no service. Nada. Any time I tried to restore with the custom file from sn0wbreeze, the restore would error in iTunes. So... I can't install the custom 3.1.3 file from sn0wbreeze without iTunes erroring... and if I install 3.1.2 and jailbreak, I lose my service. What gives? Am I missing something?