ipod classic issues syncing

When I connect the iPod I receive an error:

Attempting to copy to the disk "name of iPod" failed. The disk could not be read from or written to.

and in another window:

iTunes could not copy "name of song" to the iPod because the file could not be read or written.

I have a MacBook Pro running OS X 10.9.1 and my iPod is a click wheel 40 GB

I have done the following:

1. I have the most current iTunes software installed

2. Restored the iPod - to erase all content

3. Tried connecting and syncing iPod after a reboot of MacBook Pro

4. Tried different combinations of opening iTunes and connecting iPod (ex. connect before opening iTunes, connecting then letting the system open iTunes, etc)

5. Tried a different USB port when connecting iPod

6. Changed the manual sync properties in iTunes to limit down the number or songs being synced to 4 and I did have success with a couple songs transferring but the same error comes up "could not copy song" after the couple of songs

7. Checked integrity of each of the songs that are listed in the error - these have been different depending on the connection, reboot, etc. and all of them played just fine in iTunes

8. The iPod continually displays the "do not disconnect" message and most often there is no content syncing

9. The iPod does show up in iTunes and I can see the Summary and other tabs

Any help is greatly appreciated.

Thanks,

Eric