Try this (make sure you have a backup of everything, of course...).

To start a fresh/new Import from NUDC to Now X (and thus Address Book/iCal):

1. Open System Preferences, Mobile Me, Sync. Uncheck “Synchronize With Mobile Me”.
2. Open Now X (make sure you are using the last version 10.0.4), got to Preferences, Sync, Utilities. Click Clear Address Book, Clear iCal, Reset Sync Services.
3. Back to Preferences, Database, Maintenance. Click Clear/Clear Database.
4. Now X will now import your Contacts and Calendar from NUDC.
5. Upon Import completion, Click on the 3 tabs at the bottom of the Now X Window: Categories, Tags, Activity.
6. Go to File, Sync/Advanced Sync. Click on Slow Sync for both Contacts & Calendar. You should see this process in the “Activity” window.
7. Upon Completion, you should now have your Contacts & Calendar in Address Book & iCal. Open each and confirm all is well.
8. Quit Now X.
9. Return to System Preferences, Mobile Me, Sync. Check “Synchronize With Mobile Me”. A dialogue box will ask / Click on More Options - then adjust Contacts & Calendar to “Replace data on Mobile Me from Computer“.
10. You should now have NUDC info imported into Now X, Address Book, iCal & Mobile Me.