Upgrade Unlocked Phone to iOS 4.2?

[Epsilon88]

I took over my sister's iPhone 3G, and it has an older version of iOS. She had gotten it from her boyfriend and then had it "unlocked" or "jailbroken" from a local vendor. If I upgrade the OS to iOS 4.2, will this render my phone incapable in any way? And would it then be necessary to re-jailbreak it?

Thanks!

 

[jmcclain145]

I took over my sister's iPhone 3G, and it has an older version of iOS. She had gotten it from her boyfriend and then had it "unlocked" or "jailbroken" from a local vendor. If I upgrade the OS to iOS 4.2, will this render my phone incapable in any way? And would it then be necessary to re-jailbreak it?

Thanks!

Thread belongs under the "Hacks" section of iPhone thread, but yes you'll have to re-jailbreak and unlock if you upgrade firmware.