horizontal menu bar 3 th level unaccessible

i use the standard athaualpa menu bar. i use a simple two level menu. on hovering the item a vertical drop down box appears. works great. until today.
i added a third level and there is no way to access it. on hovering the 2nd level menu a vertical drop down box appears on the left side of the first one.
the vertical drop down box appears one item level lower than the menu item. there is no way to access the drop down menu. looking for the solution in the forum, headache all day long, what am i doing wrong ?
attachment with view on the problem added.