Hello, i got this iphone with 2.2.1 software, but i want it to downgrade to 2.2 firmware. so i read a tutorial how to do this, first step is to get into DFU mode. but i can't, everytime itunes gives an error that the phone isnt reconisble. i read something about a usb hub, but also that doesn't work. anyone knows what to do next? just to get into DFU mode. i'm using the latest version of itunes and working on a alu macbook 2.0.