I just double checked and the site is up both here at work (where it is hosted) and from my home PC (on a different network). Both could pull it up fine.
http://muhlenberg.kyschools.us/
I found some example code and adapted it to show the issue using the CSS from the simplecatch theme.
It is here:
http://jsfiddle.net/BEhvQ/209/
You can see the issue when you mouse over “About”.
“The product nested” and “Meet the team nested” are only supposed to show when you mouse over “The product”, but instead are expanded when you mouse over “About”.