Are you joining tables? Can you include the entire screenshot of the data source dialog, not just the bottom?
Thanks for your quick reply - your question/request got the brain going.
I was joining my Adherence SAS Dataset to an Agent SAS Dataset. (Basically connecting employees unique ref on Adherence table to their Agent table which contains all their details i.e. name, etc...). On the Agent dataset, i had duplicate rows - so that was causing the file to duplicate the values!
It looks like its worked - i've quickly removed duplicates and it all seems okay!
Thank you for you help - your reply solved this!