Lisp file problem if loaded on 2000i

This code does not change the dimscale if run in Model space!! The
problem is with 2000i only!

;;;;;;;;;;;;;;start;;;;;;;;;;;;;;;;;;;;;;
(defun scaling ()
(if (eq (getvar "tilemode") 1)
(progn
(setq Dim-scale (if (eq (getvar "dimscale") 0) 1 (getvar "dimscale")))

(setq Scale-key (strcat "\n Scale Factor <" (rtos Dim-scale) ">:"))
(setq Scale (cond ((getreal Scale-key))(t Dim-scale)))
);progn
(progn (if (eq (getvar "CVPORT") 1) (setq Scale 1) (setq Scale (/ 1
(xpfact))))
)
)
(setvar "DIMSCALE" Scale)
(princ)
)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun xpfact () ;by Tony Tanzillo
(- (car (trans '(1 0 0) 2 3))
(car (trans '(0 0 0) 2 3))
)
;(princ)
); end of xpfact
;;;;;;;;;;;;;;;;;;;end;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


I am loosing it why is this happening? When auto loading with Appload
Suite, or acad.lsp, or even if directly loaded inside mymenu.mnl
the file will not change the dimscale. If the user is "manually" loading
the file (via drag and drop explorer/Acad), the file will execute.

Not sure if am clear on this, there is no problem with "unknown
command". it will not change the dimscale if the (scaling) is run in
Model space! Worst thing that I can not reproduce it. It is happening to
one user on 2000i, (tried it with XP, W98)two diff. boxes with same results!

Any help will be appreciated

Viliam