Where did the subquery in the first piece of code come from?
You have changed the SQL generation to ANSI, by the looks of things, that will also, obviously, make a difference?
I have seen this sort of behavior before, when I was doing XIr2 beta testing. Setting cardinalities did make a difference to the code generated, see here:-
https://bobj-board.org/t/52392
The problem could also be driver related, IMO.
Mak 1 
(BOB member since 2005-01-06)