Shortly after upgrading, I went to Apple’s instruction page and followed the steps to activate Find My i Phone.
Set the email address and password to your i Tunes login credentials. I found my phone on a map and sent myself a threatening “You’ll never get away with it” message. But from that point on, I started getting email connection failure notifications.
(The redacted bit is an email address that I use for both a real account and as my i Tunes login.) Clicking the Settings button takes me to the new Mobile Me account setup screen in Settings, so it’s obviously that account is what’s causing the problem.
I think there’s a missing step in Apple’s instructions: sync your phone to i Tunes agan after setting up your new Mobile Me account.
Update 11/26/10 As you’ll see, the solution I proposed turned out not to be a solution at all—the error messages returned after a few hours.
All these failure notifications happened, though, .