iPod No successful song transfer to iPod Nano 8G

Hey guys, I'm having a problems with my iPod (as you might have guessed) recently, iTunes is not transferring ANY of the songs I put in it.

I manage my music manually, so when I drag and drop the music I want into MUSIC under the iPod it transfers it, no problem. As if nothing was wrong.. But when I disconnect the iPod.. nothings in it.. no songs.. images... zilch

Feedback is my goal.. so if anyone could help me with this. it'd be great.. yeah.. thanks