I have an iPhone 3g that was on FW 2.2. I did a shift restore to a custom 3.1.2 and all seemed to be fine. After I finished my Cydia updates I took the phone out of airplane mode and that's where the trouble started. The voicemail alert has been going off continuously and the phone now says no service. How do I stop this and return the phone to its jailbroken & unlocked state? Please help!!