it's been issued for a long time since 4th Gen. ipod had came out in the market. what funny thing is that it is happened on windows many times. on the mac, it occurred sometimes. now, solution? as far as I know, there is no solution if Apple doesn't fix that.
I found a solution and it's working fine for me now. You need to go into iTunes Edit-Preferences-Devices, and delete the backup for you ipod. then EXIT iTunes and then sync with your ipod again, time will be corrected based on the time of your computer.