nice menus not working in firefox under b2nature

Somehow, b2nature is keeping me from having nice menu's work in firefox.
The problem is when I hover over de mouse menu nothing happens not even the mouse arrow turning into a hand because of the a elements.

Here's what I tried:
I tried nicemenus in b2nature in all other browsers: works
Tried nicemenus in bartik under firefox: works as well
Went looking at the issue queue for nice menus. many had issues with firefox but then with different themes and for different reason that don't seem to apply here.