unable to sync

Any advice please?

Never had a problem downloading CD's and music from iTunes onto my classic i pod until yesterday. Downloaded a CD to my library which was successful, on disconnecting there was no music on the ipod, totally blank. I only have music downloaded onto the i pod with no games or films and have enough memory space.

As it seemed corrupted I plugged the i pod back in, to return it to factory settings. This worked so tried to sync the i pod, initially the sync appeared to work but could only download half of the tracks. A box appeared which stated 'attempting to copy to the disk 'users i pod' failed. The disk could not be read from or written to'

Also the library page appears to freeze or take a long time to work. I've tried to sync a few times with the same message appearing. Also when playing some of the tracks that were supposedly successful downloaded the songs are jumping half way?

Would love my music back

Many thanks for any help

Angela