I have a question about my son's iphone 3GS, he bought it unlocked and jailbroken and it works fine in the US but when he travels out of the country it will not connect to a network. I have recently downgraded his baseband since it was at 6.15.00 so his GPS works and the phone will be more stable. He tells me it would lose signal and have other problems so now I hope that has been resolved. What can I try to get the phone to work overseas?

Thanks in advance for any help