A number of iPhone 4S owners are complaining that the 'phone' section of the device is not working properly, and is "eating" their SIM cards.
The problem seems to be affecting customers running iOS 5.01, with those suffering reporting frequent error messaged detailing "invalid SIM", even though they know the SIM cards have worked perfectly well with other phones.
User Jacob 923 posted on an iPhone forum: "I have the same problem guys it says i have full bars. when i call someone it does not connect the call i cannot receive or receive text. Im starting to feel as if i purchased an ipod."
Another user, Edward Sopahan, wrote: "So far I have had my iPhone 4S for 2 weeks and it worked flawlessly before the 5.0.1. After the update the signal was unstable, battery drain [an] issue, [it has become] difficult to place call (call failed), and gives me invalid SIM every few hours. I'll be using my old iPhone 4, fortunately I didn't update it with 5.0.1. I hope Apple come out with a better update fix ASAP."
Restarting the phone seems to work for most users, although only temporarily.
Other suggestions included restoring from iTunes, switching off 3G, or taking it into an Apple store for someone behind the Genius Desk to sort it out.
Apple have yet to comment on the issue.
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