Ever since I got the iOS 4.0 working on my 3G it slowed my phone to a crawl. Text messages took about 20 seconds to come up if they came up at all. The Maps program took just as long. The iPod crashed more than ever. Then I saw the Lifehacker article on how to How to Downgrade Your iPhone 3G[S] from iOS 4 to iOS 3.1.3 and I figured it was worth a try.
The instructions on Lifehacker are kind of long and not exactly straight to the point. The instructions I am posting below are summarized from the Lifehacker article and they include using both Windows 7 and Mac OSX. I used Mac OSX for the RecBoot software because I had easy access to it and the Windows version isn't as easy to setup (since I didn't try it I shouldn't say if it really is or isn't).
Basic iPhone 3G Downgrade Instructions:
- Download iOS 3.13 for the 3G phone here.
- Plug your iPhone into your computer.
- Power it down by holding the sleep/lock button and sliding to power off.
- Once it's powered down, press and hold both the sleep/lock button and the home button for ten seconds.
- After ten seconds, release the power button but continue holding down the home button.
- If you did it right, iTunes will pop up a window telling you that it's detected an iPhone in recovery mode and your iPhone's screen will be black. If it didn't work, start from the beginning and try again. (For me it just appeared in iTunes without showing the window!)
- Click on the iPhone in iTunes (select it).
- Hold down the shift key and click Restore which should open up an explorer window. The shift key is for Windows only. I'm not sure what key it is for Mac OSX.
- Select the downloaded iOS 3.1.3 file and let the restore complete.
- Download RecBoot for OSX here. Note: This is where I switched to the Mac. If you use a Windows machine you can download RecBoot for Windows; it requires .NET 4.0 and some other software program. Good luck.
- In the downloaded RecBoot software there will be two programs. Click and run the RecBoot program called RecBoot Exit Only which will cause the iPhone “exit recovery mode” and to restart.
- Sync your newly downgraded iPhone
Good luck. Needless to say I'm on the waiting list for the iPhone 4. However this whole experience plus the iPhone 4 issues have me considering leaving the iPhone family (not seriously, at least not at this point). Maybe once my contract is up on my iPhone 4 I will.