Since the singing window for 4.3.5 is now closed, this guide is no longer valid. If you didn't manage to get it to work before approx 20:00 on 17/10 then you are out of luck. The process simply won't work now. You cannot downgrade a baseband once Apple has stopped providing the firmware signature for it.
To avoid any unnecessary bumping of the thread, it is now closed from further posts.
To avoid any unnecessary bumping of the thread, it is now closed from further posts.