Are you using a Mac with a Retina display?
Yes I am
I do not know about PrE, but Adobe Photoshop has been having some major display issues with the Retina display, and are working with Apple to try and sort those out.
Maybe Steve recalls something specific with Retina and PrE.
Yes. Many people with Retina displays are experiencing this weird, buggy behavior. Unfortunately, Apple hasn't yet provided a patch for it.