>No, I have to reason to believe that there is any such guarantee. While that would certainly be nice, I have to way of knowing whether that's true.
>

this is equivalent to VFP 70 ( but add a rn field ):

SELECT TDATA.*,TGROUP.TOTAMT ;
	FROM (SELECT *,RECNO() rn FROM Orders) TDATA;
	JOIN (SELECT MAX(rn) rn ,SUM(AMT) TOTAMT FROM ;
			(SELECT OrdNbr,RECNO() rn ,AMT FROM Orders);
			Orders GROUP BY OrdNbr) TGROUP;
	ON TGROUP.rn=TDATA.rn