After rebuilding permissions, running cron, flushing caches, dotting the i's and crossing the t's, I've come the the bug report zone. I'm out of ideas, at this point:
-All pages on my site are unavailable to the anonymous user, even though they function perfectly for all other users/roles!
-The header, sidebar, and nav functions all load as they should, but the actual content of the page is replaced with a simple statement of "You are not authorized to access this page."
I feel as though there's something simple I'm missing, but I'm just not finding it. I've been all up and down this site and a few others, to no avail. Is there some other means for checking/correcting this? Dblog registers an "access denied" event, but with no detail to go on. Any help would be greatly appreciated. Running PHP 5.2.17 with Drupal 6.22 on Bluehost, for what it's worth.
Edit: I did check for user 0. 0 was missing, so I went ahead and added him (or is it her?) and re-ran the usual housekeeping (cron, update.php, rebuild permissions) ...But still no love. I had a look at .htaccess, but I must confess that I'm not sure what I'm looking for in there. Nothing appears to be related to user access, anonymous or otherwise. For what it's worth, this is on the development site. The live site does exactly what it's supposed to, and has exactly the same host, settings and modules (as far as I can tell). This suggests to me that there's something I'm missing.... If they really WERE the same, they'd work the same! ;) Thanks for the suggestions so far! I have other modules to review, but they're waiting on this issue...