I just had a really weird incarnation of the memory bug, unrelated to rendering. In fact, I hadn't rendered at all. I was running sims in the cloth room. Suddenly, I got a message that said "you are running out of memory, please restart soon" or something along those lines. And the file was nuked. In very odd manner, too. The only thing I could see was the dynamic top I'd been working on. The figure, the other clothing, the jewelry and hair, etc. - all gone. They showed in the heirarchy menu, and they showed in selection menu, but I could not get them to be visible. I started over again from scratch, and everything's fine.