We already mentioned that the new UltraSn0w unlock for iOS 4.2.1 was to be released yesterday and now you can, we would love to know if you have had any problems with your new update.
iOS 4.2.1 was released about a week ago and a new RedSn0w jailbreak update followed it, well today we would like to hear from those that have used the new UltraSn0w unlock for iOS 4.2.1 that works on the iPhone 3G, iPhone 3GS with baseband 04.26.08, 05.11.07, 05.12.01, or 05.13.04 and those that have iPhone 4 with baseband 01.59.00.
This update could be a little tricky, iDB say that this is a little “special” and won’t be as simple as downloading UltraSn0w from Cydia, that is unless you are one of the above basebands, you do need to update your baseband to 06.15.00.
This is for the iPhone 3G or 3GS only, apparently you cannot update the iPhone 4 to baseband 06.15.00, and it will only work on iPhone 4 on baseband 01.59.00. Please read the following, as it is very important.
WARNING – YOU DO THIS AT YOUR OWN RISK! PLEASE UNDERSTAND THE CONSEQUENCES OF UPDATING TO 06.15.
1. There is no way to come back down from 06.15, and there’s no hiding the baseband version from Apple. You’ll be voiding your warranty in a very obvious way.
2. If some future baseband comes out with a critical fix, you won’t be able to update to it if it remains down in the 05.xx sequence (then again, you wouldn’t update to it if you wanted to keep your unlock anyway).
3. Starting with FW 4.2.1 if you have 06.15 on your iPhone you won’t ever be able to restore to stock firmware (it will fail). You’ll need to only restore to custom IPSWs (then again, if you’re unlocker you should already be doing that).Certainly don’t update to 06.15 if you don’t need to! Only do this if you need the unlock and you’re stuck on 05.14 or 05.15, and you’re willing to assume the above risks.
Please do let us know if you have tried the UltraSn0w unlock for iOS 4.2.1 as this will let other readers know if they should try it or not, your input and knowledge is very important to others. Thanks