Well, you can't say they didn't warn you.

Apple released an update for the iPhone this week that brings the Wi-Fi Music Store to the device, as well as several security fixes and enhanced features. But, as expected, it also turns iPhones that were unlocked to run on cellular networks other than AT&T's in the United States into little more than emergency call boxes.

Macworld reported two iPhones in its office with SIM (subscriber identity module) hacks did not work after the update was installed. A message prompted the phone's owner to install "an unlocked and valid SIM card" before the phone could be completely activated. It's almost like the phone was in the same pre-activation limbo stage that frustrated many iPhone users waiting for activation the first weekend the device went on sale.

Gizmodo is reporting that both the original SIM cards as well as new SIM cards from AT&T won't work in iPhones that had been activated with the original SIM card, then unlocked from the network. That could present a huge problem for iPhone owners who thought they could get around the reactivation process by getting a new AT&T SIM card.

Other reports are trickling in of similar experiences. It appears that those who downloaded the "jailbreaking" software application that lets you install third-party software aren't running into the same problems if they are still using AT&T's network. However, they are reporting that their third-party applications have vanished upon reactivation.

Did you hack your iPhone, and have you had similar problems after installing the latest update? Let us know.