I have jailbroken my 3GS (old bootrom) on IOS 4.3.1 (8G4) with baseband 05.13.04.
I have been struggling for more than 2 weeks to unlock it with ultrasn0w 1.2.5
without success since there are always errors when installing ultrasnow....(difficult to read since the screen is scrolling)
I try to restore it with Itunes 10.5.2 without any success.
All I want is to be able to use it in future as a phone whatever the IOS or the baseband,
provided I keep my GPS running.
Thanks for helping me. (since no way I can buy another iphone)