My iPhone just rang once and the message "Blocked missed call" appeared on the screen. The Recents list shows a call from "Blocked Caller." What the heck is this? I don't have any blocked callers that I know of, and I can't find any settings for this, either on the iPhone or on my AT&T (USA) account.
Intel 32-bit, Windows XP, iPhone 3G 16GB OS 3.1.3 iTunes 9