after struggling for 2hrs, I finally found the solution!
I had bought a disabled ipod G2 on an auction site... It looked impossible to unlock it! I couldn't go into the DFU after trying at least a hundred times (eventually, I found out that the home button is lazy...)!
Anyway, after re-reading the same procedure over and over, and working for a device manufacturer myself I was pretty sure there existed a SW only solution to do that (I can't imagine that people in the production need a roughly 30 sec procedure to flash a FW).
I eventually found it! it is called RecBoot. There are 2 versions, 1.3 seems to be the latest for Win7 32bits (the one I used) and there is another one for Mac which is already at v2.2. I loved those guys who made it! it took me about 30minutes to get my ipod working (I needed to reinstall itune)! (just load Recboot, choose the mode and plug the iphone/ipod in)!
Just google it and download it (about 700k).