I’m not sure how this ghost-town blog has survived on WordPress version 1.2 for years. I’ve only occasionally had to delete some spam comments.
Today I made the various updates with the thorough instructions on the WordPress Codex, and got up through version 2.9.2, which is where I’m at now.
When I try to get to version 3.0.6, it fails to display the home page properly, leaving just a blank, white page. Admin is fine. So revert to the backup database and WordPress directory.