Do as follows:
1. From the menu select Company - Preferences
2. Click Company Preferences tab
3. Click QuickBooks Synchronization on the Left.
4. CHECK "Sync manufacturers part no#.
5. Click OK to save your changes and close the preferences window
Now we need to re-sync the items so that MPN will come (note you only need to do this once)
6. Click Company - QuickBooks Synchroinzation -- Selective Sync
7. Check Inventory Item, Non-Inventroy Item and Inventory Assembly
8. Click OK
9. Wait until the sync is done even if it appears the program is not responding.