d.mon error

[Salah BENABDALLAH]

 I installed GRASS4.0 in another SUN IPX machine. However, I
got an error in running d.mon as shown below..I couldn't 
display anyimages..Do you have any ideas ?

Many thanks

--Salah Benabdallah
e-mail: salah at alyssa.rsinet.tn

=======Error Message ============

Mapset <workspace> in Location <spearfish>
GRASS 4.0 > d.mon
                    MONITOR MENU


Making sure that the graphics monitor is running

     1 - start a graphics monitor
     2 - stop a graphics monitor

Choosing a graphics monitor for your graphics

     3 - select a graphics device for output

RETURN - quit

> sun

Enter name of graphics monitor to start
Enter "list" for a list of known monitors
Enter "list -f" for a list with current status
Hit RETURN to return to menu
> sun
Graphics driver [sun] started
Error - Could not complete locking process for monitor <sun>.
Lock file is 
Problem selecting sun. Will try once more
Error - Could not complete locking process for monitor <sun>.
Lock file is 

hit RETURN -> 
                    MONITOR MENU