1. back up your ipod in itunes
2.click restore to factory settings, I know you dont want to but there is no other way
3.after restoring click set up as new ipod/iphone/ipad.
4. it should remember your ipods serial number, so it wont ask you to rename it, at least for me it didn't.
5. go to the summary page and click sync it wont sync any thing to it
6. go to the tab that says music and check sync music, it will show now that you have music data in the bar at the bottom that shows whats on your ipod/iphone/ipad.
7. repeat step 6 for all of your movies/podcasts/tvshows
8. to get your apps back on your ipod go to apps and click install next to each one.( make sure that your still in the ipod/iphone/ipad summary page.)
9. final step click sync now all of your apps/music/ect. will be put back on your ipod/iphone/ipad
your welcome i hope this fixes your problem btw for 6-8 make sure you are in the summary tab, also this will not put the restrictions password back on.