Basically I have a 3gs, I have upgraded to the 4.3 firmware using itunes 10.2 on a macbook pro, which is my laptop that contains none of my music etc, it was just a stupid mistake to update. However I need to downgrade and do not know how to do so. I need to downgrade my firmware as my main mac G5 OS X version 10.4.11, therefore I do not have the new itunes. Somebody please help as I need to sort my iphone out A.S.A.P! Many thanks