I've had a 3G for ages but thought I'd jailbreak and unlock my old 2G so my girlfriend could use it. It had been working fine without a SIM for ages (just for games etc.) but when I turned it on yesterday it would only allow emergency calls and I couldn't get in. I've turned it on and off loads of times and it always just goes back to the emergency calls only screen. It said I needed to connect to itunes and restore, so forced the phone to recovery mode and connected to itunes. itunes downloaded the software no probs and tried to install, but quickly came up with the error "The iphone could not be restored. An unknown error (23) has occured. I'm stuck!! Does anyone know what I need to do?