Randomly, you are unable to use ctrl-c/ctrl-v/ctrl-x shortcut keys in
the pgadmin edit window, but you can use the right click menu.
You can make the shortcut keys work again by clicking in another widget
in the same editor window and then clicking back to the main edit box.
Video link to show a really good example of this happening:
http://www.youtube.com/watch?v=e6WKzaB3J1c