Thanks. I now see that DISTINCT can't be moved within the plan as I thought. This is exactly the thinko that I was hoping someone would expose.
I've decided to abandon the DISTINCT clause. The view is more general and sufficiently fast without it, and callers can always add it themselves to achieve what I was doing in the explicit query.
I appreciate your time.
-- Reece Hart, http://www.in-machina.com/~reece/, GPG:0x25EC91A0