I want to downgrade to 2.2.1 from 3.1.3 on an iPod touch 1G. It's getting very old, and recently it's started doing a very odd thing. Basically, when you plug headphones in (on 3.0) the volume bar appears underneath the control buttons. However, on my iPod, it might be 5 minutes, or it might be 5 seconds, before plugging in headphones, the volume bar disappears and the music stops playing. Irritatingly, if I press play again without the volume bar, I can just about hear my music over headphones. Currently I've been trying to get my iPod back to a firmware which didn't implement the hiding volume 'feature', which was 2.0. I've hit a brick wall quite a few times, to begin with it was the (20) and now the (1600) error in DFU mode. I've tried jailbreaking, I've tried iREB. Any ideas on why my iPod won't let me downgrade?