Some animations appear jerky.

A long time ago, I had a problem where skirts on creatures and some animations in towns moved jerkily instead of smoothly. Then I found a way to fix it, and I think I found it here on the HW forum. Unfortunately, my computer crashed, and I had to completely rebuild it. And I'm facing this problem again, but now I don't remember how to fix it. Does anyone know, has anyone encountered this, and remember how to eliminate this annoying bug?