It took awhile, but I got it. Long story short, I had to trial and error my way through not the WP index.php script, but the one that I downloaded with the template I modified. The eventual culprit?
I had switched my archive list from a big list to a dropdown menu, and apparently it didn't like that. Everything else in the template is cut and paste what I had there all along, but when changing the archive list back to a full month-by-month list (and eventually deleting the gaudy thing!), it worked.
Thanks again for all your tips, suggestions, help and positive vibes, macmanx... just don't go too far away, okay? laugh
have you met tony?