Hi dune1982,

> But when I click on the resulting cylinder and move it, suddenly the result from the
> first booleandiffrence apears again. Why is that?

Hmmm, I don't know why that would happen. I tried running that script over here and I can't seem to get the reappearing behavior to happen when I move the booleaned cylinder result.

Maybe you're seeing the result of a history update, what happens if you select everything and run Edit > History > "Disable update" button before trying to move the object does that make any difference?

- Michael