If I update my 3GS to 4.0, will I lose my unlock?

[benflick]

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.

 

[Applejuiced]

It will NOT work.
It will lock up again.
You need to be JB to be unlocked on 3G and 3GS models.
And with the new bootrom you have no option right now but to wait or go to official 4.0 and only use it with official carrier.

 

[thelatinist]

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.

No, you cannot unlock your phone unless it is jailbroken. If you rely on an unlock, you have to wait until a new tool comes out that can jailbreak your phone.

By the way, the only iPhone that can be upgraded without losing its jailbreak is the 2G.