arghh... (also, you mean loops/views, not cels/loops). Yeah, I broke this when I "fixed" things so that copying among view cels with the same palette just did a direct copy (instead of re-interpreting RGB colors).
Well, you can work around it in the meantime by making the bottom cel the same size of the one you're copying from, then adjusting (and wouldn't you need to do that anyway? If you're trying to make a small version of the plunger, you'd want to copy the old one into a same size cel, and then re-size it by SHIFT-dragging a border).