Turn it off and hide the icon. ANNOAUTOSCALE is something that you don't want.
Also keep the scalelist as short as possible: In OPTIONS go to 'User Preferences' -> 'Default Scale List' and delete all scales except 1:1
Only when you need a new scale, you should add it:
(defun c:1:1 ()(MaakSchaal 1))
(defun c:1:2 ()(MaakSchaal 2))
(defun c:1:5 ()(MaakSchaal 5))
(defun c:1:10 ()(MaakSchaal 10))
(defun c:1:20 ()(MaakSchaal 20))
(defun c:1:50 ()(MaakSchaal 50))
(defun c:1:100 ()(MaakSchaal 100))
(defun c:1:200 ()(MaakSchaal 200))
(defun c:1:500 ()(MaakSchaal 500))
(defun c:1:1000 ()(MaakSchaal 1000))
(defun c:1:2000 ()(MaakSchaal 2000))
(defun c:1:5000 ()(MaakSchaal 5000))
(defun c:1:10000 ()(MaakSchaal 10000))
(defun MaakSchaal (waarde / e schaal)
(command ".undo" "be")
(setq schaal (strcat "1:" (itoa waarde)))
(setq e (getvar "EXPERT"))(setvar "EXPERT" 5)
(command ".-scalelistedit" "A" schaal schaal "Exit")
(setvar "EXPERT" e)
(if (and (zerop (getvar "TILEMODE"))(zerop (getvar "VPMAXIMIZEDSTATE"))(eq (getvar "CVPORT") 1))
(princ "\nThe scale has been added to the scalelist.")
(setvar "CANNOSCALE" schaal)
)
(command ".undo" "end")
(princ)
)
To purge scales that are not in use, you can add (command "._-scalelistedit" "_delete" "*" "_exit")
to your startup-routine.