iPhone 3GS Baseband Downgrade New Update To Release Today – Two weeks ago iPhone Dev Team announced that an upcoming Redsn0w update will be soon to Fix iPhone 3GS issue for those who were unable to downgrade from the iPad baseband 6.15.00 to lower baseband in order to enjoy the unlock without 6.15.00 baseband risks.
Also he has found that the reason of blocked 6.15.00 downgrade is due to the OTOH (check the tweet below)
MuscleNerd: After day of debugging why reverted 3GS had no service, found it was blocked for unrelated reason! OTOH I figured out how change IMEI
MuscleNerd: Other than that testing hiccup, the revised payload seems fine…will release improved downgrade later today. Happy 4th of July!
Update: now its available to use the new improved Redsn0w from our links posted here