If you copy and Paste New a component that's positioned using a joint, in the new copy the joint is converted to a saved position. A saved position is not as useful as a joint as it's not parametric and doesn't update if the model changes. It would save time and make more sense to copy the joint as well. Editing the joint to a new point is just a couple of clicks, deleting the saved position and applying a new joint is a lot of extra effort, see screencast, file's attached.
Mark