I spent 7 hours trying to downgrade my iPhone 3G 3.1 to 3.0 on my iMac. I followed the instructions (all 63829572 of them......) to a T. Here's the gist of what I did. I connected my phone via USB, opened iTunes 9 and put the phone into DFU mode (black screen). After the message I option-clicked and restored using the .ipsw 3.0.1 firmware file. Towards the end of the restoring process I got the 1015 error message, ignored it like the instructions said. Now here's where I couldn't proceed. As soon as the error message popped up, iTunes automatically put my phone into recovery mode (screen with the USB logo). Therefore, even though I quit iTunes and launched QuickPwn, QuickPwn wouldn't recognize the device. So I started all over again and this time after the 1015 error message I quit iTunes without giving it a chance to put the phone in recovery. Note that iTunes Helper was NOT running in the background. But after I quit, iTunes auto launched and put my phone in recovery mode again. And no matter what I did, iTunes kept putting it in recovery, making it impossible for QuickPwn to do its thing. I even tried to paste that code into the /etc/hosts file in case that had anything to do with it, but it wouldn't let me save. I went into Get Info, set the owner as me and changed the access from read only to read & write. Still wouldn't let me save. Someone please tell me why downgrading seems to work for everyone else but me. What am I doing wrong? I don't care about jailbreaking, I just want to downgrade so I can have tethering back.