The weird numbers, could be due to the iPod firmware corruption, but what is causing these strange number, will also prevent you from updating the firmware.
Or else you bring it in to Apple Store for the Genuis to have a look at it if it is still under warranty, or should get the Hardisk replaced at a 3rd Party service vendor.
But do put your iPod in Disk Mode
- Connect it to a USB 2.0 port at the back of your PC and not to those at the front and dont use any USB hub while syncing or rectoring.
- Disconnect all USB devices
- Stop using email.
and Restore the iPod firmware when iTunes recognised it.