An anonymous reader writes "We have started seeing an increase in iPhone issues related to battery life and overheating. All of them seem to be related to users upgrading their devices to iOS 6.1. Furthermore, Vodafone UK today began sending out text messages to iPhone 4S owners on its network, warning them not to upgrade to iOS 6.1 due to issues with 3G performance. The text reads, 'If you've not already downloaded iOS 6.1 for your iPhone 4s, please hold off for the next version while Apple fixes 3G performance issues. Thanks.'"