The iPhone Dev team had released an updated version of UltraSn0w last week to unlock iPhone 3G and iPhone 3GS which they believed would resolve all random issues that were reported by users.

They have just published a post in which they have confirmed that the latest version of UltraSn0w 0.9  has fixed most of the issues reported by iPhone 3G and iPhone 3GS users.

They have also provided more details on the list of fixes in case you are still seeing some problem and provided tips on how to resolve them wherever applicable.

Here is the list of issues fixed in UltraSn0w 0.9 and tips and clarifications to resolve them if you are still facing an issue:

• Unusual battery depletion is almost always caused by people choosing to “Restore from backup” instead of “Setup as new iPhone” when iTunes asks you.  This isn’t caused by either the jailbreak or the unlock, but it’s a common 3.0 snafu.  The fix is to just re-run the official 3.0 restore and choose “Setup as new” this time.  Your music and apps and all that will still be synced, but you’ll get rid of any conflicting wifi, bluetooth, or carrier settings.  Then just re-run redsn0w and install ultrasn0w.
• Remember, ultrasn0w works with hacktivated phones too, but don’t outsmart redsn0w into thinking you don’t need hacktivation!  If you don’t plan on using an official sim, don’t activate via iTunes with such a sim.  Just keep your unofficial sim at all times and let redsn0w and ultrasn0w handle hacktivation 🙂
• T-Mobile in the USA doesn’t use the 3G frequencies that the iPhones support, so turn off 3G in Settings->General->Network.  (Some T-Mobile territories gracefully hand down to Edge mode, but most do not).
• Certain unofficial plans have limitations on whether you can make calls and use data at the same time. That’s not unlock-related.
• Some people have installed previous versions of ultrasn0w using non-standard techniques.  While the ultrasn0w 0.9 update should have removed all previous versions of ultrasn0w, these users may have outsmarted our removal.  So make sure you don’t still see /usr/bin/ultrasn0w present if you’re at ultrasn0w 0.9 (which doesn’t have such a binary anymore).
• If you don’t need or plan to update to ultrasn0w 0.9 from a previous version, you can avoid having that red badge over Cydia by removing repo666 as a Cydia source.  Don’t worry, you can always add it back later 🙂

Hope you have found them useful. You can checkout our guides below:

• Jailbreak iPhone 3G using RedSn0w for Windows users
• Jailbreak iPhone 3G using RedSn0w for Mac users
• Jailbreak iPhone 3GS using RedSn0w for Windows users
• Jailbreak iPhone 3GS using RedSn0w for Mac users
• Unlock iPhone 3G & iPhone 3GS using UltraSn0w

iPhone 3GS users who might be still facing problems with UltraSn0w can also checkout purplesn0w, Geohot's solution to unlock iPhone 3GS.