By chance, I discovered that the ID numbers of the logs were not incrementing in a +1 sequence, but instead were skipping numbers. After checking the database with PhpMyAdmin, I found out that WordPress 2.6 had added an automatic post revision backup feature. I have no idea who came up with such a brain-dead function—every time you make an edit, it automatically saves a copy. It's like they're trying to make the database explode.
The code added in **wp-config.php** is as follows: