This is a very common issue. Postcodes in some countries change at a rate of 10% per year, so even though the postcodes in your database may have been 100% correct when they were entered, they are unlikely to be 100% correct now. The same is true for the postcode data in MapPoint - it is a snapshot which may have been close to 100% correct at one time, but it is no longer 100% correct and going more out of date each day.



Unfortunately, there is no method for updating the internal MapPoint postcode data. There are some workarounds - like geocoding on street address instead of postcode (assuming you have full addresses), or getting your data geocoded in another program and then mapping your records in MapPoint using the lat/long value resulting from this geocoding work.