Microsoft SQL Server uses outdated values in stored procedures
while @poid is not NULL
    BEGIN

        Update Item set Sales = (Select Sales from V_ITEM_Hierarchy where POID=@poid) where ItemID=@poid

        Select @poid = i.ItemID
        from V_ITEM_Hierarchy t inner join Item i on (t.POID = i.POID)
        where ( abs(coalesce(t.Sales,0)-coalesce(i.Sales,0)) > 0.0001

    END

while @poid is not NULL
BEGIN

    Update Item set Sales = (Select Sales from V_ITEM_Hierarchy where POID=@poid) where ItemID=@poid

    set @poid = null

    Select @poid = i.ItemID
    from V_ITEM_Hierarchy t inner join Item i on (t.POID = i.POID)
    where ( abs(coalesce(t.Sales,0)-coalesce(i.Sales,0)) > 0.0001

END

DECLARE @poid INT

DECLARE item_cursor CURSOR FOR
 Select i.ItemID
   from V_ITEM_Hierarchy t inner join Item i on (t.POID = i.POID)
  where ( abs(coalesce(t.Sales,0)-coalesce(i.Sales,0)) > 0.0001

OPEN item_cursor

FETCH NEXT FROM item_cursor INTO @poid
WHILE @@FETCH_STATUS = 0
  BEGIN
     Update Item set Sales = (Select Sales from V_ITEM_Hierarchy where POID=@poid) where ItemID=@poid

    FETCH NEXT FROM item_cursor INTO @poid
  END

DEALLOCATE item_cursor