'kill-region' replaces primary selection?

I believe this is a fairly recent change in XEmacs behavior. 'kill-word' currently replaces the primary selection with the killed word, where previously (circa b29, I think) the primary selection was left alone. Is this an intentional change in behavior and, if so, how might I go about reverting to the old way? It used to be really easy to do a semi-automatic query-replace with the old bindings and I miss it. :) Thanks, Daniel -- A tranquil city of good laws, fine architecture, and clean streets is like a classroom of obedient dullards, or a field of gelded bulls -- whereas a city of anarchy is a city of promise. -- Mark Helprin