Hi
Solve my own problem - adding info here - in case somebody is interested.
When Xorg is started, (in my case startx), with the vert-veiwer environment, Xorg defaulted 1024x768 resolution. I ran xrandr <hight rsolution> after window maker start. I did this via autostart as it work for openbox. This does not appear to work the same way for Windowmaker. I had to manually restart Windowmaker (via the menu) to accept the new size. Instead, I created and modified a xorg.conf file with the "preferred" option to for the higher resolution at start up.
Regards
Gerhard