While running Mavericks, I added
Control-N as shortcuts for Preview.app. Sort of Emacs-like page turning. It worked fine.
After upgrading to Yosemite, these keyboard shortcuts no longer work. Deleting them from the Shortcuts list in System Preferences and creating them again does not fix the issue. As you can see in the second screenshot, the shortcuts
^P do not appear in Preview.app's "Go" menu. I seem to remember that when the shortcuts did work, the "Go" menu showed them.
If there is a shortcut conflict, I haven't been able to find it. Thanks!