As it turns out I was also on NW19 NRT-SIN on the 21st, in the very last row of Y (66). I also noticed the flicker of reading lights on and off at times, but actually attriubted it to people bumping the light switchs in the turbulence -- which was constant during the flight and quite significant at times (as a whole, I would say it was about the "roughest" 7 hours I've flown -- but I was also feeling a little under the weather).

I did not notice the lights doing the same thing during the return the next day (I came right back on NW20, so the same aircraft) but that could have been because the behavior was less noticable in the early morning and daytime.

I didn't even attempt to watch the movie; it looked awfully pinkish to me!

But we did have a lot of room to stretch out, that's for sure. Not crowded at all.

Steve