Wow. My Note2 finally got the 4.3 update, so I odin'd it up, re-rooted then started uninstalling apps that I had already gotten rid of on 4.1.2 and then discovered that my share button in Gallery crashed every time.
After reading this and knowing I hadn't frozen/uninstalled the Paper Artist app, I went ahead and uninstalled Paper Artist and what would you know? It's now working! One less app in my share menu cluttering it up too, so that's also a win.
So thanks, your suggestion led me to a fix much more quickly than me stuffing around with my phone trying to work it out!