I've updated my iPhone 4 from 5.0.1 to 6.1.3 via sn0wbreeze, then installed the untether. The baseband is still on 1.59.00, and now I seem to not be able to get service. Or at least constant service, it shows 1 bar and AT&T, but constantly switches between that and "No Service." I have an iPhone plan, so I didn't need an unlock. Any solution?