Recently my whole library disappeared and after I got it back and synced all my music back to my iPod when I play music on my ipod and then sync to update the music that was played will not show as having been played but different music all together will show up as having been played instead.
From where did yoiur library disappear? From the iPod or from your iTunes-equipped computer? How did you get it back? Did you rebuild from a backup or reload all of your CDs and purchased bits?
The common suggestion for this kind of mishap is to use the restore function on the iPod when you connect to iTunes. This will nuke the memory, check for new iOS and restrat the unit. Then you can use iTunes to reconfigure the stuff you want to have loaded on the iPod.
Instructions here: http://support.apple.com/kb/HT1339
Message was edited by: David Bogie Chq-1