Milonic JavaScript Menu

I have a horizontal menu set up with images as the main buttons; below each button/image a vertical Milonic menu drops down. By default the menu is aligned to the left edge of each image; what I would like to do is center-align the menu relative to the center of each image. I've tried a few things ...

At first I thought I was doing something wrong in my code, but then I noticed that this sample page exhibits the same behavior (in Safari)

http://milonic.com/menusample8.php

When I load the page the header text is yellow.

If I mouseover a header, the text turns black, and stays black when I move ...