Are you sure you did both Recovery and DFU properly? The ONLY way DFU will NOT work is if the device is physically damaged to the point of preventing it even going into said modes (which software cannot do, yet) or if you aren't doing it properly.
Continue to try until your device is detected and you can restore. Try doing different times on the first holding step by 1 second increments.
bighost: download a normal ipod 2.2.1 ipsw and restore to it with dfu
jeckel: it is possible to break dfu mode through software, i have done it. if you send the patches manually while the screen is white just before the restore and you pull it out of dfu mode it will actually not go into dfu anymore...idk how to fix it either so i dont suggest it