I’ve been having this really annoying error lately ever since that carrier update that Apple released to add support for AT&T’s new microcells. The exact message is this:
Having finally decided today to google around and figure out what the devil was wrong, I stumbled across this (coral) forum thread on macrumors and found that the problem is caused by the AT&T Carrier Logo package. The problem is that the carrier update doesn’t recognize the altered carrier settings. The solution is to uninstall that package via Cydia, sync with itunes and apply the carrier update, then reinstall the package. Boom, done.