Attention jailbreakers: We've just received word from BigBoss that Apple stopped signing iPhone OS 3.1.2 restore packages today, making it impossible to restore to 3.1.2 without a workaround. This only affects the iPhone 3GS, the third-gen iPod touch, and late-model, second-gen iPod touches; other iPhone OS devices do not use signed restore packages.
So what does this mean? Well, because Apple released iPhone OS 3.1.3 earlier this week, the Apple servers will only let you restore to 3.1.3, even if you have an older 3.1.2 restore package lying around. And since the current jailbreak tools only work on 3.1.2, updating to 3.1.3 will leave you jailbreak-less — at least for the time being. But wait, there's a workaround!