ipod won't sync with itunes because unknown error(-69)

Before the newer version of itunes, all my music sync on to my ipod with no problem. Now after I updated to the most recent itunes, my music won't sync. I restored my ipod and I have the latest version of irunes. But it always say unkown error(-69). I just want sall my songs on my 80gb classic, because it had all my songs on there before with no problem til this new version and me restoring my ipod.