Realizing the amount of customers with unlocked iPhones on T-Mobile’s network, Magenta has released a note to all employees regarding the new iPhone OS 3.1.3 software version that was released yesterday. T-Mobile states that, before troubleshooting the iPhone, employees should ask the subscriber what software version they’re currently using, as the new firmware might cause issues with T-Mobile services. Being the iPhone guru that I am considered, here are the details on this new “software update”. The update is meant for iPhone 3G/3GS owners (though it is available to iPhone 2G owners) and it was released to resolve issues with reporting the correct amount of battery life on 3GS models. The software update also resolves issues with some instances where 3rd party apps would fail to launch. If you’re using an iPhone 3G or 3GS on T-Mobile’s network, DO NOT update to OS 3.1.3, as it will upgrade your baseband to 5.12.01 making it impossible for you to unlock (at least for now) and use the iPhone on T-Mobile’s network. iPhone 2G (first generation) owners are not affected, and can update to the new OS. Details can be found here. Hopefully, if the rumors turn out to be true, and the iPhone comes this summer, we will no longer have to worry about updating our software version each time Apple releases an update.