I have a new-bootrom 3GS on 3.1.3. Jailbroken with Spirit, Unlocked with Ultrasn0w. I want to update to 4.0, but I need an unlock. I don't need a jailbreak. I have the 5.13.04 baseband from 4.0, and I'm wondering if I update to 4.0, will my phone stay unlocked? I know you can uninstall Ultrasn0w from Cydia, and your iPhone will remain unlocked. I have updated the frimware on iPhones before, and they have stayed unlocked if the new firmware didn't include a baseband update. Before I try this, what do you think? It should work, especially if I update, not restore.