width problem in submenu with 2 rows, 3 cols

Hi,
I want to make a horizontal menu like in my attached graphic. All works fine, except the width of the submenu grows to 800px, with 400px empty space on the right. It should be 400px (first row = 1 col 400px. Second row = 2 col 200px). I Think the menu sums the widths up, and i cant find where i turn this off.
I Hope you can understand me Any help will be appreciated

Hi
you must use the param "subwidth=400" like explained in the doc on the parent item
Ced