Hi, my fren just bought an iphone 3G frm low yatt. It;s an Australian iphone 3G frm wat the model no. stated.
He bought frm low yatt, and i try to install free software like facebook into his iphone, but cant' use at all. Will keep crash. all the software frm cydia n installer installed all cant use. It seem like the phone is locked down.. i want try to restore the phone to unjailbreak version but i afraid will effect the phone to locked down n cant use the maxis simcard. ANy expert there know what i can do?

and they installed some cydia n itunes apps which i cant delete at all.. or synced in itunes.