Hi
I have a LG GT540 optimus. It was on 1.6, I used a tutorial to use a kdz to flash to 2.1 stock, then again to 2.1 fastboot, then used 2.3 cyanogen installer to upgrade to 2.3
I then realised I couldn't use an unlock code on a non stock ROM, so stupidly I used kdz manager to flash back...