- See:
How to sync music to your iPod when your library is bigger than your iPod storage space
Make sure that you still do not have the box(es) checked to synce your entire library
Try:
- Reset the iOS device. Nothing will be lost
Reset iOS device: Hold down the On/Off button and the Home button at the same time for at
least ten seconds, until the Apple logo appears.
- Unsync all music and resync
- Reset all settings
Go to Settings > General > Reset and tap Reset All Settings.
All your preferences and settings are reset. Information (such as contacts and calendars) and media (such as songs and videos) aren’t affected.
- Restore from backup. See:
iOS: How to back up
- Restore to factory settings/new iOS device.