Well, I had some issues with multiple users that I cleared up with some
registry tweaks (thanks to the folks on the Seti@Home message boards).

Now here's some more info:

If I run the S@H application (system tray) at startup (or manually), so the
'green dish' is in the tray, the 'screensaver' works properly.  If I exit
the 'green-dish' application, the 'screensaver' flashes and exits.  Isn't it
supposed to start the 'green-dish' application when it's not open
automagically?