[AccessD] A momentary lapse of reason: Part II

Hi Guys 
Following on from my recent post the Union query  works. That is it returns 
24498 rows. The problem is the tbl_PPMSupplier  contains 23320 rows and 
tbl_Rejection has 100 rows.  I expected the result view to have  total of the 2 
tables eg 23420 rows. the Union Q is returning  1078 rows more that 
expected. Any suggesstions? 
TIA 
johnc 
SELECT Distinctrow  tbl_PPMSupplier.AP_No, tbl_PPMSupplier.SupplierID,  
tbl_PPMSupplier.GRQ 
FROM tbl_PPMSupplier 
WHERE ((tbl_PPMSupplier.AP_No) Between "2009-ap04" And  "2009-ap09")   
order by tbl_PPMSupplier.AP_No 
UNION ALL SELECT  tbl_Rejection.AP,tbl_Rejection.SupplierID,  
tbl_Rejection.QuantityAtFault 
FROM tbl_Rejection;