iPhone 3GS 3.1.3 new bootrom jailbreaken
after around 3 months when I was forced to do a restore of my iphone to 3.1.3 without SHSH blob saved I finally managed to jailbreak it. It is true that I had to spend some money.
To make things short I found on youtube a way to activate the iphone 3GS without the original simcard buy buying a dits Phonebook card.
After I've put this sim to my 3.1.3 Iphone I managed to activate it with iTunes then I just used Spirit to jalbreak the phone and installing the last version of ultrasn0w did the trick for me.
Unfortunatelly the phone is still on 3.1.3 and not on 4.0 or 4.0.1 as I would like but still at least I can use it.
If someone find a way to jailbreak 4.0 on 5.12.1 bootrom just post a replay please.