Ludo --
Rickard's plugin worked fine. The reason I didn't download the whole updated package and install, is that I've done extensive mods to the interface (reworking modules so they're standards compliant and validate in strict XHTML), and I didn't know if running the update.php would kick everything back to the defaults.
As you've probably guessed from my questions, I know just enough PHP to be dangerous. I teach XHTML and CSS in college courses, but PHP is still a few miles down the road for me. I'm presently trying to piece together a script for webwired.org that will take the payer's email and payment status from the PayPal IBN module, insert it into a database, then reference it prior to validating the new user's registration form. The sticky part (for me, anyway) is merging something like that with my present authorization scripts.
It's all mind-numbing after a while.
Thanks to Ludo, Elzar, snapsolutions for the replies. Very helpful.
gDane