You may have tried this already, but if not, it might help to reinstall the software (iTunes in this case). The iTunes/iPod package has a bunch of different parts and anyone of them may have gotten corrupted or messed up. Having a fresh install could alleviate any problems. Your songs (both from CDs and the iTunes Store) won't be deleted during this process. If you want to back them up anyway, open My Computer and go to: My Documents\My Music, then copy and paste the iTunes folder to your desktop. •Close all windows. •Open Control Panel (through the Start button or Start > Settings). •Open Add or Remove Programs. •Select iTunes, then click Remove. •Select Yes. •Do not restart when prompted. •Go back into Add or Remove Programs, remove any iPod Updater applications that are listed, just like you did for iTunes. •Now restart your computer.
This is part two :)
•Open My Computer, double click Local Disk C, double click Program Files.
•Do you see the iTunes folder? It may or may not be there. If so, right-click over the iTunes folder, select Delete, select Yes.
•Do the same for the iPod folder (right click, delete, yes).
•Minimize all windows and right-click over the Recycle Bin. Select Empty Recycle Bin.
•Restart your computer.
Go download iTunes and install it. After that whole thing is done, connect the iPod. I really hope this works for you because the other fix is a little confusing if you haven't done it before.
Your computer manages different programs in different ways. Your problem may stem from the fact that the iPod Service isn't set properly.
1.Disconnect your iPod and quit iTunes.
2.From the desktop, right click over My Computer and click Manage.
3.In the left side panel, double click Services and Applications, then double click Services (right underneath).
4.Double click iPod Service in the right hand panel.
5.Click the Stop button under the General tab and leave the iPod Service Properties window open.
6.Connect your iPod and wait until you see it in My Computer (be patient, it may take awhile).
7.Click the Start button in the iPod Service Properties window.
I know I should have asked this first. Which OS are you using; Windows or Mac OS?
I hope that in your case it is the cable since I have had these case where the drives showed but would not mount and I could not access the drives which was a HDD failure.