Hi hope this doesn't seem like too much of a dumb question...I haven't updated my iPhone software in a while!

Ok so I have an iPhone 3G, it was a replacement given to me in an applestore for a broken iPhone.

Running 3.1.2, baseband 05.11.07.
JB/UL using Pwnage tool (Mac) & Ultrasnow.

I have a Three (UK) sim card, which is why I unlocked on 3.1.2.

Three UK is now (as of iPhone4 release) an "Official" carrier.

I want to upgrade to iOS 4.1 - do i still need to unlock if Three are now an "official" carrier?

I'm not too worried about Jailbreaking at the moment, but I don't want to update to 4.1 only to discover that I've upgraded my baseband and thwarted any future possibility of an unlock if it doesn't work with three!

Any advice on my best option for upgrading would be great!!

Apologies if this seems like a dumb question... I've been out of the loop for a bit (been unlocking since v. 1.0.2 so not new to this!) and just want to make sure I'm choosing the best route with the myriad of new JB/unlock options now out there!

Thanks in advance!

-Suze x

make sure u install Custom Firmware that doesnt Update ur baseband
then u can use ultrasn0w to unlock ur phone

Custom IPSW is made with PwnageTool, don't trust custom IPSW made by someone else.

iClarified - iPhone - How to Jailbreak Your iPhone 3G Using PwnageTool (Mac) [4.1]

use pwnagetool 4.1.2 - which you can find here: Dev-Team Blog - 20102010 event

Hey both, thanks for the responses

I ended up just taking the plunge and going the pwnagetool route, which has worked fine (and in response to my own question, the Three sim card was not recognised as an "official" carrier, so I did need the unlock) so all is good!
And dare I say it, 4.1 does seem speedier than 3.1.2 for me...good times!
Will look forward to the upcoming 4.2 pwnage tool so that I can finally be fully up to date!
Thanks for your help!