When I double click an object in Xara Pro X sometimes it opens the object in a new file.

I say sometimes because it doesn't do it under all circumstances. I think it is just on some cloned objects. I normally use double click on an object as a shortcut to the shape tool (used to be called shape editor tool). Even though it only does it on some objects, when it decides to do this it is consistent for that object.

Any clues as to what is going on here?