Hi,
This might help.
Is it possible that you clicked on the Link Data Wizard instead of the Import Data Wizard.
The link wizard requires you to have a Primary Key (i.e. a unique reference) for each record, for example an account number. If no column designated as a primary key MapPoint will use your zip code. If there any double ups you will get the message that only 8 unique records have been mapped in this set.
The import wizard should sort the problem.

Hope this helps
Regards
Stephen Kilbee
www.cover-point.co.uk