Apple has stopped signing iPhone OS 3.1.2 firmware from today. So, from today, all those iPhone 3GS and iPod Touch 3G users who did not store their TSS for OS 3.1.2 via Cydia cannot restore OS 3.1.2 or older firmware. From now on, all these users will be forced to restore to latest OS 3.1.3.
If you fall into that category and have not store your TSS, please make sure you are very careful with what you do from now until the next jailbroken firmware. Be sure that you don’t do anything to your iPhone that may result is requiring a firmware restore. You have been warned!
We recommend you to install & learn OpenSSH and learn how to SSH into iPhone so that if anything goes wrong with your iPhone 3GS or iPod Touch 3G, you may perform certain repairs without a firmware restore.
3g / 2g users need not worry as you don’t need Apple to sign your firmware files.