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"Let us think the unthinkable, Let us do the undoable, Let us prepare to grapple with ineffable itself, And see if we may not eff it after all." Douglas Adams

Disabling a Stubborn Field Test Mode

Some time ago, I turned on Field Test Mode on my iPhone 4. I then dutifully backed up that phone for ages, restoring that backup to my new iPhone 5 when I got it last year.

Then I tried turning off Field Test Mode, which came over in the backup. And it wouldn’t stay turned off.

After much searching I found a solution that, for now, appears to have solved the issue: enter the number into Notes and then paste the number into dialer, instead of typing in the number (from this helpful Apple support thread).