There are a couple of situations in which tracks may synchronize to an iPod but not be visible on the iPod (even though they've been copied to the device):
- If you're using an older version of MediaMonkey that doesn't support the device or firmware on the device.
- If iTunes is preventing MediaMonkey from updating the iPod's database or if the iPod database has been overwritten by iTunes. To solve this, you must first disable 'Open iTunes when the iPod is attached' in iTunes, and make sure that iTunes isn't configured to automatically sync media to the iPod.
- Then select the iPod in MediaMonkey, right-click, and Rebuild Database. This will rebuild the device database based on whatever files are actually on the device.
- If this fails, then try resetting the iPod's firmware using iTunes.
After this is done, try syncing from MediaMonkey again, and the synced content should be browsable on the iPod.