Quote Originally Posted by AndyFC91 View Post
Hello. I'm under 05.12.01 as well. What are my options? Can I downgrade? I'm willing to do anything to get my iPhone service for T-Mobile working again. thanks!
Please read above -- Oletheros made it very clear early on, if you're running a 3GS with the 05.12.01 baseband, there is absolutely nothing you can presently do. A solution will not be presented until end of June/beginning of July at the earliest.

If you're on a 3G with the 05.12.01 baseband, you can try jailbreaking and using FuzzyBand or BBUpdaterExtreme, but the reports from people who have tried are _EXTREMELY_ hit or miss, and you can cause some serious (and some permanent) problems if you attempt to do the baseband downgrade incorrectly.

Sorry to give you bad news, but 05.12.01 is not currently unlockable.