UK customers using the iPhone 4S handset have been warned by Vodafone and Three’s network in Austria not to update to iOS 6.1 which went out at the end of January.
Vodafone has said that since the software’s release it has had cutomers reporting difficulty, including limited 3G performance.
A statement from Vodafone read: "Some customers may occasionally experience difficulty in connecting to the network to make or receive calls or texts or to connect to the Internet. Apple is working on a solution to their software issue. These connection problems are intermittent."
Meanwhile a statement released by Three's network in has similarly asked users to hold off on installing the update: A Google translations of the statement reads: "Dear 3 customer! The update of the iPhone 4S on iOS 6.1 can currently cause connectivity problems. We responded quickly and are working with Apple on a solution to the problem. For this reason, we recommend not to install the update for the time being. We will inform you immediately if there is a solution. Your 3 ServiceTeam."
Other users on different networks have not reported any problems.
Apple has not responded to the statement from Vodafone.