Until I can figure out why my posts and index aren't rebuilding properly, I've disabled my category archives. They weren't really updating anyway. I've isolated the problem to the rebuilding of those archives, and it was giving 500 errors with every published post or comment, and I've decided having the archives up without being updated isn't worth having to do a manual rebuild every time anyone posts, updates a [published post, or comments. If you're looking for something particular, you can still search the blog in the normal way, but those who use the category archives just to find things on topics you're looking for (if anyone even does that) won't be able to do that anymore, at least until we can figure out what the problem is and resolve it.
Update: Never mind. I guess it was being fixed as I wrote this post. The category archives now have post excerpts rather than whole posts, which is the way it should have been in the first place. I'm not sure why it defaults to whole entries in the archives, which just leads to ridiculously large files.