I have a Sprint iPad. I'm trying to cancel my data service, but when I go to "View Account", it gives me the message "This device has already been activated and cannot be reactivated at this time" - it won't actually show me my account. I tried to go to Sprint's website to make an account there to handle it, but it won't take my iPad's serial # to set up an account. About a month ago, my iPad had some firmware problems and I got it replaced at the Apple store. I restored it from an old backup. Since then I've been having a ton of Invalid SIM issues with the new one and haven't actually been able to get my cell data to work in the first place. Has anyone had this kind of problem after moving a SIM card to a new iPad? I googled the error message above and it gives zero hits, which is worrying. Do I just need to go back to the Apple store?