Ipod Syncing Problem

I let my sister borrow my ipod for a while. She has windows. Now i have my ipod back and i tried to copy music to it. It says that it is syncing but it stays at 1 out of how ever many songs i am copying. Then a minute later an error comes up saying that i do not have access privileges to copy the songs to the ipod. When that happeneds an error comes up saying that my ipod have been removed.

I have checked all the folders premissions and they are all read and write. I tried to copy songs to my iPhone and they go on there fine. I have tried the following:

Restoring Ipod
Re-installing itunes
Restarting My computer

Thanks

I've been trying all night. I download floola and tried to copy songs onto my ipod from there but it does not work. It just doesn't upload fast at all and then i get an error. I will be bringing my ipod to the apple store tomorrow to see whats going on.