In one of the tutorials Art mentions that jogging is switched off on some of the screens so that you do not accidently jog the machine out of position once it is set up. This is because ( I think) jogging only affects one set of co-ordinates, and if you have set other co-ords, or are not running in machine co-ords, the two sets will get out of reference with each other.
On my Turn program, jogging works only on the "Manual" page as you are setting your work up. Once you move page, say to input code directly to the machine via the key board, or to enter and run a program, jog will not work.
On my Mill program, as far as I can remember, jogging only works on screen 1