My second ipod classic (120g) cannot draw in music

Question

I have my first ipod classic (120),it work well.
Recently I boung my second ipod classic for my wife.
Both we want to use same itune library which build by my first ipod, but we want some different contents between these two ipod.
I found when my second ipod connecting with itunes, I cannot draw music in, from
itune library which make by first one.
After I upgraded itune software to 8.0.2, finally I found some musics can be drowed in, but some musics cannot.
But My first ipod always work normally.
I bring this second ipod to the two ipod shops which near my home, it shows ok, every music can be drawed in. So they told me they cannot help me.
Would you please give me some idea?

Answer 1

Here is so cold, nobody want to help me.
Any, I solved this issue by myself.
Some music can be draw to ipod, and some music cannot, just due to the link
betwwen musics and itune was destoried. So that if you want to draw the musics
which link destoried, it not allow you to do because it cannot link to the target music.
To solve it is quite simple, if your itune folder still keep all music fles.
If you had same issue, please follow the following step carefully.
1. Back up your itune folder to safety place, like other hard disk or folder.
* This is very important step, without it you may lost all you have.
2. Delete all music