Queries :: Table With Duplicate Records - Return Distinct Data For Each Client

I have a table with duplicate records (which is ok) and I want to return distinct data for each client.

It works fine when there is only two fields returned however, when I add a third field to the query it no longer returns only the Distinct records - I am getting Duplicates returned.

I.E

SELECT DISTINCT tblClient.ClientNo, tblClient.Name
FROM tblClient

Works fine with only the Distinct records for each client returned

However

SELECT DISTINCT tblClient.ClientNo, tblClient.Name, tblClient.Address, tblClient.OrderValue
FROM tblClient

Now returns Duplicates!

Is there a limit to the number of fields to be returned using DISTINCT or what else could be the problem? Should I be doing this some other way?