My iPhone will randomly (this might be caused by something, but I have yet to discover the cause) make all of my incoming calls go straight to my voicemail until I go to my voicemailbox and change the setting for it. It will also not recieve texts during this period. What could be the cause of this and how would I go about fixing this? I am on AT&T with an unlocked and jailbroken 8gb iPhone 3g currently using a Winteroard theme with firmware version 2.0.1 if that helps.