Just going to show that I don't actually search my own database often, I discovered in the MT redesign that the Atomz search index was all frelled up, and since I'd turned off automated reindexing, it had remained frelled up for a lengthy period time. Sorry about that. I've turned the scheduled reindexing back on.

One disadvantage to how I'm doing this WIST implementation in MT is that I can't use MT's built-in search engine. But, hey-presto, no biggie, because I can still use Atomz -- and, it seems, Atomz is actually a better choice, since it gives contextual results. Cool.