MrWCF: This rule also exist in other variants, like in Portuguese checkers, and it does matter, sometimes. The question is that you can only jump once over each piece, in your move. To guarantee that you respect this, the "mechanism" is that the jumped pieces are only removed in the end of your move. If pieces were removed just after jumped, you would be ignoring that rule.

I don't know if I was clear: the question is not the piece taked (jumped) twice. The question is that a taked (jumped) piece works like a "wall" - that's the spirit of that rule!