Apple recently seeded a second revision of its iOS 5.0.1 firmware, and besides decrypting key files that aid in the legality of a Siri port, the update seemed to bring nothing new to the table. Some speculated that the second update had something to do with Apple’s continued international rollout of the iPhone 4S.
It turns out that the new iOS 5.0.1 (Build 9A406) is meant to fix SIM-related errors that a limited number of iPhone 4S customers have been experiencing.