Basically, the movement of slow motion is not as smooth as before. That is what jumps. I don't think sceenshots could illustrate this problem. Turning off resampling was necessary to stop interlacing artifacts within a single frame, the problem I first wrote about. I do render in the BEST setting. It's as if the performance of the rendering software or interpolating has deteriorated over time, but a part of a computer can't degrade (like analog tape gets dirty or a car rusts), can it?