I often will borrow groups and layers from one document and drag them into a new or a different PS document to borrow the layers and formatting so I am not starting over from scratch with a design that I just need to re-work into a different size. But in the last two weeks, when I drag the layers over, they start mysteriously changing into other layers that I did not drag over. What is causing this bug? It wasn't there before as I have performed this action many times in various projects. I am using PS CS6 on a MacBook Pro.