Hi, Picked up a new iPhone 4 today from Apple store it's factory unlocked. However, I can't get it to downgrade firmware from 4.2.1 to 4.1 so I can jailbreak it using Limera1n. I tried the method of altering the hosts file but that doesn't work, believe the issue is I don't have a SHSH file from previous firmware. What options do I have now? I understand there's a tethered jailbreak but I'd prefer not to do that. Thank you for your input.