Hi, Firstly, this is about an official , end of contract, unlock not to do with Jailbreaking etc. I tried to make that clear in the title but sorry if you were misled. I am with Tesco Mobile in the UK and my iPhone 4 is now out of contract. I asked Tesco to unlock my phone and they have done so free of charge. I have received a text saying that my phone is unlocked and to insert my new carrier's sim card and sync with iTunes. All good... I've got a SIM card from 'Three' and it should be activated by tomorrow so I can give it a try then. I delayed activation on my Three contract until my unlock came through as I was told it could be up to 28 days. It was only 5 days in the end. My question comes from the fact I am running iOS 5 Beta 3 and like some other people, I am getting an error when I sync my phone. The error is: "iTunes could not check for an update to the carrier settings for your iPhone. An unknown error occurred (1659)." I'm worried, perhaps prematurely as I've not tried it yet, that this will prevent the unlock from being recognised and wondered if anyone else out there has any experience of this? Has anyone successfully (or unsuccessfully) unlocked an iPhone 4 while running iOS 5 Beta 3? Thanks for reading, Craig.