http://support.apple.com/kb/TS2830
Error occurs while syncing music
The error will most commonly occur while syncing music. This issue can be resolved by following these steps:
Select the iPhone or iPod touch in iTunes under Devices.
Click the Music tab and under the Sync music option, choose Selected playlists.
Deselect the Voice Memos playlist.
Click Apply and then click Sync.
If the above steps do not resolve the issue, check the device and the iTunes library for duplicate voice memos. If you find any duplicate voice memos, delete the duplicates and then sync.
If those steps do not resolve the issue, then follow these steps:
Select the iPhone or iPod touch in iTunes under Devices.
Click the Music tab and deselect the Sync Music option.
Click Apply and then click Sync.
After the sync is complete, reselect the Sync Music option.
Click Apply and then click Sync