SQL Query returning inflated numbers

My query:

SELECT     somast.fsono, somast.fstatus, SUM(soitem.fquantity) AS itemsOrdered, SUM(shitem.fshipqty) AS itemsShipped
FROM         somast LEFT OUTER JOIN
                      soitem ON somast.fsono = soitem.fsono LEFT OUTER JOIN
                      shmast ON somast.fsono = shmast.fcsono LEFT OUTER JOIN
                      shitem ON shmast.fshipno = shitem.fshipno
GROUP BY somast.fsono, somast.fstatus
HAVING      (SUM(soitem.fquantity) <> SUM(shitem.fshipqty))

Select allOpen in new window

is resulting in the itemsOrdered being multiplied by the number of items and the itemsShipped being multiplied by something as well.

I'm not sure what more info you guru's need/want.