Right Arrow Disappears

Hi,

I use maximenu for joomla 1.6, Version 5.15 with advanced parameter.

When I choose a background color in the parameter for a menu item on the second level the right-arrow (to the third level - items) disappears. What can I do?

My site is still in test-mode under test2.blueprints.de

No idea? Perhaps a picture helps to understand. I add in maximenu-params in the menu the background color "brown" and then the arrow is away ...