iPod Can't sync Gen II iPod after failed attempt to transfer music between Macs

I followed the directions step by step on the Apple page for using my iPod to transfer music between my Macs. Converted it to use as a disk, etc. The first time I did it, I got some error on the transfer and the music didn't show up on the new Mac. I was having a party, needed the music back on the iPod, so I switched it back to working like an iPod. The files were wiped, iTunes synced it back to normal, no problems. After the party, I tried the whole process again. Same error, so the music didn't transfer. I remembered I have an extra external drive, so I'll try that. My problem is now iTunes claims there is 21mb worth of files on my iPod and won't sync the music. The iPod shows there is no music at all. I click the iPod link on my Finder and it shows there is nothing. Is there someway to totally wipe my iPod clean and start over? Is this an iTunes issue or an iPod issue?

Oh yeah, I've tried "Restore", but keep getting told that the iPod contains files in use by another program. iTunes seems to be the only program thinking there are other files.

Thanks,

Bryan

no suggestions? It's taking hours to use my backup CDs, I was hoping to learn the "proper" way to do it. iTunes still shows my iPod as having 21 gigs of files and now it shows about 7 gigs of music. I can't get rid of the 21 gigs of files.

Thanks,

Bryan