i have had the same problem. its not with your ipod at all. its itunes. do you get your music from limewire? if you do, your music will go to shared. if you right click on the song with the exclaimation point, you should find an option called find? im not sure because i fixed all my songs and dont remember how. it will bring up a window where you can go through all of your folders and click on that song if you can find it. now it will sync