Can a unlocked phone remain unlocked after a restore in Itunes to the stock Apple firmware.
Am talking about Iphone 3G , 3.0 OS Jailbroken using Redsn0w and unlocked using ultrasn0w.
Very sure. Try it yourself if u want.
Once u do a restore all hacks are gone. I think the 2G baseband sometimes survived a restore but not 100%. I know ultrasnow doesn't though.