Sorry for the late update, all. Internet access is a rare luxury in the afterlife.
Actually, I had forgotten about this. I took a sample not long after the initial activity on this thread. It tasted off. Not terrible, but just not good either. I was trying to decide whether I should dump it or not when work stuff got in the way again, and eventually the airlock dried up. It was really bad after that, so I ended up pitching it.
I've since made a better batch, so autolysis must have played some role. It does happen, I guess, but it must take a while to become noticeable.