Apple has made iOS 4.3.1 available to its iOS-based devices. The system update, which is available from iTunes, mostly fixes a number of bugs, such as cellular network connection/activation and graphics and image problems. The update is free.
The update is for iPhone 4 (GSM only) and other latest Apple devices. That's why Verizon's iPhone shows current software. One of the fixes was for cellular connectivity. Since the update was for GSM only that may mean only the GSM version needed fi... (continues)