Hi Paul,

> I don't know if that's a bug or not, but if it is, it's maybe a "good" bug.

I see - what's happening here is when you click down on a construction line it is getting selected (even though the appearance does not change), and then it is trying to drag it like a regular object. However, clines don't support some of the other infrastructure for getting transformed yet, so that's why they get deleted. But this is easy to tweak, I've tuned this up so that the line will actually drag in this situation (and you can also apply any of the transform commands on them).

You can still remove it by clicking it and then using Delete.

But these are some of the reasons why there isn't an "official" persistent construction line yet - you probably don't want them to get selected like regular objects, but there isn't currently any way to lock an object to prevent it from being selected and still remain snappable.

- Michael