Apple is getting very smart with each release of their iPhone OS.

For all of us in the Apple Developer Community, it was a welcome announcement with the 4.0 OS was announced last week with a ton of highly anticipated features and functionality improvements (of most important is that of multitasking).

Well, here’s the deal, if you install 4.0 on your iPhone you have to pay close attention to the disclaimer that Apple put out once you log into the iPhone Dev Center.

The key phrase in the above is, “…dedicated exclusively to iPhone OS 4 beta application development.”

Essentially once you’ve upgraded to 4.0 there’s no way of going back to 3.x.

That being said, never tell those of us in the tech community the word never. there IS in fact a way of undoing what you have done and get your iPhone back to the 3.x OS rev.

Hopefully this doesn’t get me kicked out of the Apple Developer’s Network, but I felt it my duty to help and assist those others that I see in the forum that are scratching their head trying to figure how to get around this.

Here’s the deal (very simple too).

Get your iPhone into DFU mode

  1. Turn off your iPhone.
  2. Hold down the power and home button.
  3. When you see the Apple logo, release the power button but continue holding the home button down.
  4. Open iTunes and wait for it to tell you that its in restore mode.

Next you’ll need to initiate a recovery using the 3.1.2 OS rev (note: 3.1.2 NOT 3.1.3). Use your favorite search engine to find the .ipsw file.

Your iPhone will error out and be stuck in the DFU mode – but that’s ok…

After that, you’ll need to cross over the Apple Supported Line and run the Blackra1n unlocking tool. After you “make it rain” your iPhone will reset and you will be back in business.

Disclaimer: I was shown this workaround by one of my Twitter Peeps, and I won’t divulge their identity, in case they don’t want to take the global hit for this. I, again, felt compelled to share with my fellow developers as I was not happy with being stuck in a non production capable mode (I can’t afford to have a handful of iPhones sitting around just for development purposes). I’m not making that Cupertino money just yet.

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