I just restored my phone to 1.1.3. Then, I called up ATT and deactivated the phone and removed the data plan. I thought I could jailbreak my phone again and just use my ATT service without the data plan, but I can't seem to downgrade... Could someone help me? Whenever I try to downgrade, now it says, "The iPhone could not be restored. An unknown error occurred (1)." Is it still possible to downgrade? And jailbreak so I can use another sim?