Hey Josh,
After a lot of frustration I finally figured it out.
My div.menu was wrapped in div.header > div.header-jpeg
div.header was position: relative
div.header-jpeg was position: abosolute
Removed both positions and voila the menu stops dropping behind the slider.
Just a bit of a pain to re-write the css to get the same look but se la vie.
Have a great day!
Pat